/* ══════════════════════════════════════════════════════════
   STYLE UTAMA — Media Pembelajaran Interaktif Informatika
   ══════════════════════════════════════════════════════════ */

:root {
    --blue: #58a6ff;
    --blue-light: #1a2744;
    --blue-dark: #79c0ff;
    --green: #3fb950;
    --green-light: #0d1b14;
    --green-dark: #56d364;
    --purple: #bc8cff;
    --purple-light: #1e1728;
    --purple-dark: #d2a8ff;
    --orange: #d29922;
    --orange-light: #2d2400;
    --red: #f85149;
    --red-light: #2d1215;
    --gray-50: #0d1117;
    --gray-100: #0d1117;
    --gray-200: #21262d;
    --gray-300: #30363d;
    --gray-500: #8b949e;
    --gray-700: #c9d1d9;
    --gray-900: #f0f6fc;
    --white: #161b22;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.6);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.25s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

/* Touch-friendly: hilangkan tap highlight & 300ms delay */
a, button, [role="button"], .grade-card, .chapter-card, .puzzle-slot, .puzzle-block,
.cw-cell, .dd-draggable, .dd-droppable, .flashcard-wrapper, .glossary-letter {
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

/* Pastikan target sentuh minimal 44px (WCAG) */
button, .btn, .btn-sm, .btn-back, .btn-home, .btn-tf, .btn-dark-toggle,
.quiz-option, .content-tab, .flow-tool, .glossary-letter, .puzzle-block {
    min-height: 44px;
    min-width: 44px;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: #0d1117;
    color: #c9d1d9;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ═══════════════ HEADER ═══════════════ */
.main-header {
    background: #161b22;
    color: #f0f6fc;
    border-bottom: 1px solid #30363d;
    padding: 14px 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    position: sticky;
    top: 0;
    z-index: 100;
}
.main-header h1 { font-size: 1.3rem; font-weight: 700; letter-spacing: -0.3px; }
.header-sub { font-size: 0.8rem; opacity: 0.75; margin-left: auto; }

.btn-back {
    background: #21262d;
    color: #c9d1d9;
    border: 1px solid #30363d;
    padding: 8px 14px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    transition: var(--transition);
}
.btn-back:hover { background: #30363d; }

.btn-home {
    background: #21262d;
    color: #c9d1d9;
    border: 1px solid #30363d;
    padding: 8px 14px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    transition: var(--transition);
    margin-left: 4px;
}
.btn-home:hover { background: #30363d; }

.btn-logout {
    background: #21262d;
    color: #f85149;
    border: 1px solid #30363d;
    padding: 8px 14px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    transition: var(--transition);
    margin-left: auto;
}
.btn-logout:hover { background: #2d1215; }

#headerUser {
    color: rgba(255,255,255,0.9);
    font-size: 0.85rem;
    font-weight: 600;
    margin-left: auto;
    white-space: nowrap;
}

/* ═══════════════ MAIN CONTENT ═══════════════ */
main {
    flex: 1;
    padding: 24px;
    max-width: 1100px;
    margin: 0 auto;
    width: 100%;
}

/* ═══════════════ HOME / GRADE SELECTION ═══════════════ */
.home-container { text-align: center; padding-top: 20px; }
.home-title { font-size: 1.8rem; margin-bottom: 6px; }
.home-subtitle { color: var(--gray-700); margin-bottom: 32px; font-size: 1rem; }

.grade-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.grade-card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 28px 20px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: var(--shadow-sm);
    text-align: center;
    border: 3px solid transparent;
    position: relative;
    overflow: hidden;
}
.grade-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}
.grade-card .grade-icon { font-size: 3rem; margin-bottom: 10px; }
.grade-card .grade-number { font-size: 2.2rem; font-weight: 800; }
.grade-card .grade-desc { color: var(--gray-700); font-size: 0.9rem; margin-top: 6px; line-height: 1.4; }
.grade-card .grade-badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    margin-top: 10px;
}
.card-k7 { border-color: var(--blue); }
.card-k7 .grade-number, .card-k7 .grade-icon { color: var(--blue); }
.card-k7 .grade-badge { background: var(--blue-light); color: var(--blue); }
.card-k7:hover { border-color: var(--blue-dark); background: #1a2744; }

.card-k8 { border-color: var(--green); }
.card-k8 .grade-number, .card-k8 .grade-icon { color: var(--green); }
.card-k8 .grade-badge { background: var(--green-light); color: var(--green); }
.card-k8:hover { border-color: var(--green-dark); background: #0d1b14; }

.card-k9 { border-color: var(--purple); }
.card-k9 .grade-number, .card-k9 .grade-icon { color: var(--purple); }
.card-k9 .grade-badge { background: var(--purple-light); color: var(--purple); }
.card-k9:hover { border-color: var(--purple-dark); background: #1e1728; }

/* ═══════════════ CHAPTER LIST ═══════════════ */
.section-header {
    text-align: center;
    margin-bottom: 24px;
}
.section-header h2 { font-size: 1.5rem; margin-bottom: 4px; }
.section-header .semester-badge {
    display: inline-block;
    padding: 4px 14px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 700;
}

.chapter-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 14px;
    margin-bottom: 24px;
}

.chapter-card {
    background: var(--white);
    border-radius: var(--radius-sm);
    padding: 16px;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    transition: var(--transition);
    border-left: 5px solid var(--gray-300);
    display: flex;
    gap: 10px;
    align-items: flex-start;
}
.chapter-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(3px);
}
.chapter-card.k7 { border-left-color: var(--blue); }
.chapter-card.k8 { border-left-color: var(--green); }
.chapter-card.k9 { border-left-color: var(--purple); }
.chapter-num {
    font-weight: 800;
    font-size: 1.1rem;
    min-width: 32px;
    text-align: center;
    padding: 4px 0;
}
.chapter-card.k7 .chapter-num { color: var(--blue); }
.chapter-card.k8 .chapter-num { color: var(--green); }
.chapter-card.k9 .chapter-num { color: var(--purple); }
.chapter-title { font-weight: 600; font-size: 0.95rem; line-height: 1.3; }
.chapter-meta { font-size: 0.75rem; color: var(--gray-500); margin-top: 2px; }

/* ═══════════════ CONTENT VIEW ═══════════════ */
.content-view {
    background: var(--white);
    border-radius: var(--radius);
    padding: 24px 28px;
    box-shadow: var(--shadow-sm);
    margin-bottom: 20px;
}
.content-view h2 { font-size: 1.4rem; margin-bottom: 16px; padding-bottom: 10px; border-bottom: 2px solid var(--gray-200); }
.content-view h3 { font-size: 1.15rem; margin: 20px 0 10px; }
.content-view p { margin-bottom: 10px; text-align: justify; }
.content-view ul, .content-view ol { margin-left: 20px; margin-bottom: 12px; }
.content-view li { margin-bottom: 4px; }

.info-box {
    background: var(--blue-light);
    border-left: 4px solid var(--blue);
    padding: 12px 16px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 14px 0;
    font-size: 0.9rem;
}
.info-box .info-title { font-weight: 700; color: var(--blue); }
.activity-box {
    background: var(--orange-light);
    border-left: 4px solid var(--orange);
    padding: 12px 16px;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 14px 0;
    font-size: 0.9rem;
}
.activity-box .activity-title { font-weight: 700; color: var(--orange); }

.content-tabs {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
    margin-bottom: 16px;
    border-bottom: 2px solid var(--gray-200);
    padding-bottom: 0;
}
.content-tab {
    padding: 10px 18px;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--gray-500);
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
    transition: var(--transition);
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
}
.content-tab:hover { color: #c9d1d9; background: #21262d; }
.content-tab.active { color: var(--blue); border-bottom-color: var(--blue); }

/* ═══════════════ QUIZ ═══════════════ */
.quiz-container { max-width: 700px; margin: 0 auto; }
.quiz-progress {
    background: var(--gray-200);
    height: 8px;
    border-radius: 4px;
    margin-bottom: 20px;
    overflow: hidden;
}
.quiz-progress-bar {
    height: 100%;
    border-radius: 4px;
    transition: width 0.4s ease;
    background: linear-gradient(90deg, var(--blue), #4DABF7);
}
.quiz-question {
    background: var(--white);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow-sm);
    margin-bottom: 16px;
}
.quiz-question h3 { font-size: 1.1rem; margin-bottom: 16px; }
.quiz-option {
    display: block;
    width: 100%;
    text-align: left;
    padding: 14px 16px;
    margin-bottom: 8px;
    border: 2px solid #30363d;
    border-radius: var(--radius-sm);
    background: #161b22;
    color: #c9d1d9;
    cursor: pointer;
    font-size: 0.95rem;
    transition: var(--transition);
}
.quiz-option:hover { border-color: var(--blue); background: #1a2744; }
.quiz-option.correct { border-color: var(--green); background: var(--green-light); color: var(--green-dark); }
.quiz-option.wrong { border-color: var(--red); background: var(--red-light); color: var(--red); }
.quiz-option:disabled { cursor: default; opacity: 0.85; }
.quiz-option.correct:disabled { opacity: 1; }

.quiz-score {
    text-align: center;
    padding: 40px 20px;
}
.quiz-score .score-circle {
    width: 130px;
    height: 130px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 16px;
}
.score-great { background: var(--green-light); color: var(--green); border: 4px solid var(--green); }
.score-good { background: var(--blue-light); color: var(--blue); border: 4px solid var(--blue); }
.score-ok { background: var(--orange-light); color: var(--orange); border: 4px solid var(--orange); }
.score-low { background: var(--red-light); color: var(--red); border: 4px solid var(--red); }

.btn {
    display: inline-block;
    padding: 10px 24px;
    border: none;
    border-radius: 24px;
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}
.btn-primary { background: var(--blue); color: white; }
.btn-primary:hover { background: var(--blue-dark); transform: translateY(-1px); }
.btn-secondary { background: #21262d; color: #c9d1d9; border: 1px solid #30363d; }
.btn-secondary:hover { background: #30363d; }
.btn-success { background: var(--green); color: white; }
.btn-success:hover { background: var(--green-dark); }
.btn-danger { background: var(--red); color: white; }
.btn-sm { padding: 6px 14px; font-size: 0.8rem; }

/* ═══════════════ DRAG & DROP ═══════════════ */
.dd-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    max-width: 800px;
    margin: 0 auto;
}
@media (max-width: 600px) { .dd-container { grid-template-columns: 1fr; } }

.dd-column {
    background: var(--white);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: var(--shadow-sm);
}
.dd-column h4 {
    font-size: 0.9rem;
    text-align: center;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--gray-200);
}
.dd-item {
    padding: 10px 14px;
    margin-bottom: 6px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    transition: var(--transition);
}
.dd-draggable {
    background: var(--blue-light);
    border: 2px dashed var(--blue);
    cursor: grab;
    text-align: center;
    font-weight: 600;
}
.dd-draggable:active { cursor: grabbing; opacity: 0.7; }
.dd-draggable.dragging { opacity: 0.4; }
.dd-droppable {
    background: #161b22;
    border: 2px dashed #30363d;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    transition: var(--transition);
}
.dd-droppable.over { border-color: var(--green); background: var(--green-light); }
.dd-droppable.matched { border-style: solid; border-color: var(--green); background: var(--green-light); cursor: default; }
.dd-droppable.wrong-drop { border-color: var(--red); background: var(--red-light); animation: shake 0.4s; }

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-6px); }
    75% { transform: translateX(6px); }
}

.dd-feedback {
    text-align: center;
    margin-top: 16px;
    font-weight: 600;
}

/* ═══════════════ SIMULATION ═══════════════ */
.sim-container {
    max-width: 700px;
    margin: 0 auto;
    background: var(--white);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow-sm);
}
.sim-container h3 { text-align: center; margin-bottom: 16px; }
.sim-row { display: flex; gap: 12px; align-items: center; margin-bottom: 12px; flex-wrap: wrap; }
.sim-row label { font-weight: 600; min-width: 80px; }
.sim-input {
    padding: 10px 14px;
    border: 2px solid #30363d;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    width: 200px;
    font-family: 'Consolas', 'Courier New', monospace;
    transition: var(--transition);
    background: #0d1117;
    color: #c9d1d9;
}
.sim-input:focus { border-color: var(--blue); outline: none; }
.sim-output {
    background: #1a1a2e;
    color: #00FF88;
    padding: 16px;
    border-radius: var(--radius-sm);
    font-family: 'Consolas', 'Courier New', monospace;
    font-size: 1rem;
    min-height: 60px;
    margin-top: 12px;
    white-space: pre-wrap;
    word-break: break-all;
}
.sim-steps { margin: 12px 0; font-size: 0.85rem; }
.sim-steps .step {
    background: #161b22;
    padding: 8px 12px;
    border-radius: 6px;
    margin-bottom: 4px;
    border-left: 3px solid var(--blue);
}

/* ═══════════════ LOGIC GATE SIM ═══════════════ */
.gate-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 12px;
    margin: 16px 0;
}
.gate-card {
    background: #161b22;
    border-radius: var(--radius-sm);
    padding: 14px;
    text-align: center;
    border: 2px solid #30363d;
}
.gate-card .gate-name { font-weight: 700; font-size: 1rem; }
.gate-card .gate-symbol { font-size: 2rem; margin: 6px 0; }
.gate-card .gate-output {
    display: inline-block;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    transition: var(--transition);
}
.gate-on { background: var(--green); box-shadow: 0 0 10px rgba(13,140,36,0.5); }
.gate-off { background: var(--gray-300); }

/* ═══════════════ FOOTER ═══════════════ */
.main-footer {
    text-align: center;
    padding: 14px;
    font-size: 0.78rem;
    color: #484f58;
    border-top: 1px solid #21262d;
    background: #161b22;
}

/* ═══════════════ UTILS ═══════════════ */
.text-center { text-align: center; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-2 { margin-bottom: 16px; }
.flex-center { display: flex; justify-content: center; gap: 10px; flex-wrap: wrap; }
.hidden { display: none !important; }
.fade-in { animation: fadeIn 0.35s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

table.simple-table {
    width: 100%;
    border-collapse: collapse;
    margin: 12px 0;
    font-size: 0.9rem;
}
table.simple-table th {
    background: #21262d;
    padding: 10px 12px;
    text-align: left;
    font-weight: 700;
    border: 1px solid #30363d;
    color: #c9d1d9;
}
table.simple-table td {
    padding: 8px 12px;
    border: 1px solid #30363d;
}
table.simple-table tr:hover td { background: #161b22; }

/* ═══════════════ FILL IN THE BLANK ═══════════════ */
.fill-input {
    width: 100%;
    max-width: 400px;
    padding: 14px 18px;
    border: 2px solid #30363d;
    border-radius: var(--radius-sm);
    font-size: 1.1rem;
    text-align: center;
    transition: var(--transition);
    font-family: inherit;
    background: #0d1117;
    color: #c9d1d9;
}
.fill-input:focus { border-color: var(--blue); outline: none; box-shadow: 0 0 0 3px rgba(88,166,255,0.15); }
.fill-input:disabled { background: #161b22; color: #484f58; }

/* ═══════════════ TRUE / FALSE ═══════════════ */
.tf-bar { background: linear-gradient(90deg, var(--green), #f1c40f) !important; }

.tf-statement {
    background: var(--gray-50);
    padding: 20px;
    border-radius: var(--radius-sm);
    border: 2px solid var(--gray-200);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.btn-tf {
    padding: 16px 32px;
    border: 3px solid transparent;
    border-radius: var(--radius);
    font-size: 1.1rem;
    font-weight: 800;
    cursor: pointer;
    transition: var(--transition);
    min-width: 140px;
}
.btn-tf-true { background: var(--green-light); color: var(--green-dark); border-color: var(--green); }
.btn-tf-true:hover { background: var(--green); color: white; transform: scale(1.05); }
.btn-tf-false { background: var(--red-light); color: var(--red); border-color: var(--red); }
.btn-tf-false:hover { background: var(--red); color: white; transform: scale(1.05); }
.btn-tf:disabled { cursor: default; opacity: 0.7; transform: none !important; }
.btn-tf.tf-correct { background: var(--green); color: white; border-color: var(--green-dark); }
.btn-tf.tf-dimmed { opacity: 0.3; }

/* ═══════════════ FLASHCARDS ═══════════════ */
.flashcard-wrapper {
    perspective: 800px;
    width: 100%;
    max-width: 450px;
    height: 250px;
    margin: 0 auto;
    cursor: pointer;
}
.flashcard {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.5s ease;
}
.flashcard.flipped { transform: rotateY(180deg); }
.flashcard-front, .flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: var(--radius);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 24px;
    box-shadow: var(--shadow-md);
    text-align: center;
}
.flashcard-front {
    background: linear-gradient(135deg, var(--purple-light), #f0e6ff);
    border: 2px solid var(--purple);
}
.flashcard-back {
    background: linear-gradient(135deg, #e8f5e9, #c8e6c9);
    border: 2px solid var(--green);
    transform: rotateY(180deg);
}
.flashcard-label { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: var(--gray-500); margin-bottom: 12px; }
.flashcard-text { font-size: 1.15rem; font-weight: 600; line-height: 1.5; }
.flashcard-hint { font-size: 0.75rem; color: var(--gray-500); margin-top: 16px; font-style: italic; }

/* ═══════════════ CODE PUZZLE ═══════════════ */
.puzzle-slots {
    display: flex;
    flex-direction: column;
    gap: 6px;
    max-width: 550px;
    margin: 0 auto;
}
.puzzle-slot {
    padding: 10px 14px;
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius-sm);
    min-height: 42px;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: var(--transition);
    font-weight: 600;
    font-size: 0.9rem;
}
.puzzle-slot:hover { border-color: var(--blue); background: var(--blue-light); }
.puzzle-slot.filled { border-style: solid; border-color: var(--blue); background: var(--blue-light); }
.puzzle-slot .slot-num { color: var(--gray-500); font-size: 0.8rem; }
.puzzle-blocks {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
}
.puzzle-block {
    padding: 8px 16px;
    background: var(--white);
    border: 2px solid var(--gray-300);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    transition: var(--transition);
}
.puzzle-block:hover { border-color: var(--purple); background: var(--purple-light); transform: translateY(-2px); }
.puzzle-block.used { opacity: 0.3; pointer-events: none; }

/* ═══════════════ CROSSWORD ═══════════════ */
.crossword-grid {
    display: grid;
    gap: 2px;
    justify-content: center;
    margin: 0 auto;
}
.cw-cell {
    border: 2px solid var(--gray-300);
    border-radius: 3px;
    text-align: center;
    font-weight: 800;
    font-size: 1rem;
    text-transform: uppercase;
    font-family: 'Consolas', monospace;
    background: var(--white);
    transition: var(--transition);
}
.cw-cell:focus { border-color: var(--blue); outline: none; box-shadow: 0 0 0 2px rgba(26,86,219,0.2); }
.cw-cell.cw-empty { background: var(--gray-900); border-color: var(--gray-900); }
.cw-cell.cw-correct { background: var(--green-light); border-color: var(--green); }
.cw-cell.cw-wrong { background: var(--red-light); border-color: var(--red); }
.cw-cell.cw-reveal { background: #FFF9C4; border-color: var(--orange); animation: pulse 0.5s; }
@keyframes pulse { 0%,100%{transform:scale(1);} 50%{transform:scale(1.1);} }
.cw-clues { background: var(--white); border-radius: var(--radius-sm); padding: 12px; box-shadow: var(--shadow-sm); }
.cw-clue { font-size: 0.85rem; padding: 3px 0; border-bottom: 1px dotted var(--gray-200); }
.cw-clue:last-child { border-bottom: none; }

/* ═══════════════ ENCRYPTION SIM ═══════════════ */
.enc-slider { flex: 1; max-width: 200px; accent-color: var(--purple); }
.enc-io {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 12px;
    align-items: center;
    margin: 16px 0;
}
@media (max-width: 600px) { .enc-io { grid-template-columns: 1fr; } }
.enc-textarea {
    width: 100%;
    height: 100px;
    padding: 12px;
    border: 2px solid var(--gray-300);
    border-radius: var(--radius-sm);
    font-family: 'Consolas', monospace;
    font-size: 0.95rem;
    resize: vertical;
    transition: var(--transition);
}
.enc-textarea:focus { border-color: var(--purple); outline: none; }
.enc-output { background: #1a1a2e; color: #00FF88; border-color: var(--gray-700); }

/* ═══════════════ NETWORK SIM ═══════════════ */
.network-canvas {
    position: relative;
    height: 220px;
    background: var(--gray-50);
    border-radius: var(--radius);
    margin: 16px 0;
    overflow: hidden;
}
.net-svg { position: absolute; top: 0; left: 0; pointer-events: none; }
.net-node {
    position: absolute;
    text-align: center;
    padding: 12px;
    border-radius: var(--radius);
    z-index: 2;
    background: var(--white);
    box-shadow: var(--shadow-sm);
    min-width: 100px;
}
.net-client { left: 15px; top: 50%; transform: translateY(-50%); border: 2px solid var(--blue); }
.net-router { left: 50%; top: 20px; transform: translateX(-50%); border: 2px solid var(--orange); }
.net-server { right: 15px; top: 50%; transform: translateY(-50%); border: 2px solid var(--green); }
.net-icon { font-size: 1.8rem; }
.net-packet {
    position: absolute;
    z-index: 5;
    padding: 4px 12px;
    background: var(--orange);
    color: white;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 700;
    white-space: nowrap;
    animation-duration: 2s;
    animation-fill-mode: forwards;
    animation-timing-function: ease-in-out;
}
@keyframes client-to-server {
    0% { left: 15%; top: 50%; }
    40% { left: 45%; top: 20%; }
    100% { left: 75%; top: 50%; opacity: 0; }
}
@keyframes server-to-client {
    0% { left: 75%; top: 50%; }
    40% { left: 45%; top: 20%; }
    100% { left: 15%; top: 50%; opacity: 0; }
}

/* ═══════════════ FLOWCHART BUILDER ═══════════════ */
.flow-toolbar {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    justify-content: center;
    padding: 10px;
    background: var(--white);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
    margin-bottom: 12px;
}
.flow-tool {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 8px 12px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-sm);
    background: var(--white);
    cursor: pointer;
    font-size: 0.7rem;
    font-weight: 600;
    transition: var(--transition);
    min-width: 60px;
}
.flow-tool:hover { border-color: var(--blue); background: var(--blue-light); }
.flow-tool.active { border-color: var(--blue); background: var(--blue-light); box-shadow: 0 0 0 2px rgba(26,86,219,0.2); }
.flow-tool-del:hover { border-color: var(--red); background: var(--red-light); }
.flow-canvas {
    position: relative;
    height: 400px;
    background: var(--white);
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius);
    overflow: auto;
    cursor: crosshair;
}
.flow-grid {
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, var(--gray-300) 1px, transparent 1px);
    background-size: 20px 20px;
    pointer-events: none;
}
.flow-shape {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0.9;
    transition: opacity 0.2s;
}
.flow-shape:hover { opacity: 1; outline: 2px solid var(--gray-700); outline-offset: 2px; }
.flow-shape-arrow {
    position: absolute;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0.8;
}
.flow-shape-text {
    position: absolute;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    padding: 2px 6px;
    background: rgba(255,255,255,0.85);
    border-radius: 3px;
}

/* ═══════════════ PROGRESS DASHBOARD ═══════════════ */
.progress-stat {
    background: var(--white);
    border-radius: var(--radius-sm);
    padding: 20px 16px;
    text-align: center;
    box-shadow: var(--shadow-sm);
}
.progress-stat-num { font-size: 2.2rem; font-weight: 800; color: var(--blue); }
.progress-stat-label { font-size: 0.8rem; color: var(--gray-500); margin-top: 4px; }

.badge-card {
    text-align: center;
    padding: 12px 8px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}
.badge-earned { background: var(--white); box-shadow: var(--shadow-sm); border: 2px solid var(--orange); }
.badge-locked { background: var(--gray-100); opacity: 0.5; border: 2px dashed var(--gray-300); }
.badge-earned:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }

/* ═══════════════ GLOSSARY ═══════════════ */
.glossary-search {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 8px;
}
.glossary-input {
    width: 100%;
    max-width: 450px;
    padding: 12px 18px;
    border: 2px solid var(--gray-300);
    border-radius: 24px;
    font-size: 0.95rem;
    transition: var(--transition);
}
.glossary-input:focus { border-color: var(--blue); outline: none; box-shadow: 0 0 0 3px rgba(26,86,219,0.1); }
.glossary-alpha { display: flex; gap: 2px; justify-content: center; }
.glossary-letter {
    display: inline-block;
    width: 26px;
    height: 26px;
    line-height: 26px;
    text-align: center;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
    transition: var(--transition);
    color: var(--gray-500);
}
.glossary-letter.has-terms { color: var(--blue); }
.glossary-letter.has-terms:hover { background: var(--blue-light); }
.glossary-term {
    padding: 10px 14px;
    border-left: 3px solid var(--blue-light);
    margin-bottom: 6px;
    background: var(--white);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    transition: var(--transition);
}
.glossary-term:hover { border-left-color: var(--blue); background: var(--blue-light); }
.glossary-term-name { font-weight: 700; font-size: 0.9rem; }
.glossary-subject-badge {
    display: inline-block;
    background: var(--blue-light);
    color: var(--blue);
    padding: 1px 6px;
    border-radius: 8px;
    font-size: 0.65rem;
    font-weight: 600;
    margin-left: 6px;
    vertical-align: middle;
}
.glossary-term-def { font-size: 0.85rem; color: var(--gray-700); margin-top: 2px; }

/* ═══════════════ DARK MODE TOGGLE ═══════════════ */
.btn-dark-toggle {
    background: rgba(255,255,255,0.15);
    color: white;
    border: 1px solid rgba(255,255,255,0.25);
    width: 38px;
    height: 38px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.1rem;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    line-height: 1;
}
.btn-dark-toggle:hover { background: rgba(255,255,255,0.25); transform: rotate(20deg); }

/* ═══════════════ DARK MODE STYLES ═══════════════ */
body.dark-mode {
    --gray-50: #1e1e2e;
    --gray-100: #252536;
    --gray-200: #2d2d44;
    --gray-300: #3d3d54;
    --gray-500: #8888aa;
    --gray-700: #bbb;
    --gray-900: #e0e0e0;
    --white: #1a1a2e;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.4);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.6);
    --blue-light: #1a2744;
    --green-light: #1a2e1e;
    --purple-light: #2a1a2e;
    --orange-light: #2e241a;
    --red-light: #2e1a1a;
    background: #12121f;
    color: #ddd;
}

body.dark-mode .main-header { background: linear-gradient(135deg, #0a0a1a, #0f0f28, #0a1a3a); }
body.dark-mode .btn-back, body.dark-mode .btn-home { background: rgba(255,255,255,0.08); border-color: rgba(255,255,255,0.1); }
body.dark-mode .btn-logout { background: rgba(255,100,100,0.1); border-color: rgba(255,100,100,0.2); }
body.dark-mode .main-footer { background: #1a1a2e; border-color: #2d2d44; color: #888; }
body.dark-mode .grade-card { background: #1e1e2e; }
body.dark-mode .chapter-card { background: #1e1e2e; }
body.dark-mode .content-view { background: #1e1e2e; }
body.dark-mode .sim-container { background: #1e1e2e; }
body.dark-mode .dd-column { background: #1e1e2e; }
body.dark-mode .quiz-question { background: #1e1e2e; }
body.dark-mode .dd-draggable { background: #1a2744; }
body.dark-mode .dd-droppable { background: #252536; }
body.dark-mode .info-box { background: #1a2744; }
body.dark-mode .activity-box { background: #2e241a; }
body.dark-mode .gate-card { background: #252536; }
body.dark-mode .sim-output { background: #0a0a1a; }
body.dark-mode .enc-output { background: #0a0a1a; }
body.dark-mode .progress-stat { background: #1e1e2e; }
body.dark-mode .badge-earned { background: #1e1e2e; }
body.dark-mode .badge-locked { background: #1a1a2e; }
body.dark-mode .cw-clues { background: #1e1e2e; }
body.dark-mode .glossary-term { background: #1e1e2e; }
body.dark-mode .flow-toolbar { background: #1e1e2e; }
body.dark-mode .flow-canvas { background: #1a1a2e; border-color: #2d2d44; }
body.dark-mode .network-canvas { background: #1a1a2e; }
body.dark-mode .net-node { background: #1e1e2e; }
body.dark-mode .content-tab:hover { background: #252536; }
body.dark-mode .btn-secondary { background: #252536; color: #ccc; border-color: #3d3d54; }
body.dark-mode .btn-secondary:hover { background: #2d2d44; }
body.dark-mode .sim-input { background: #252536; color: #ddd; border-color: #3d3d54; }
body.dark-mode .cw-cell { background: #1e1e2e; color: #ddd; border-color: #3d3d54; }
body.dark-mode .cw-cell.cw-empty { background: #0a0a1a; border-color: #0a0a1a; }
body.dark-mode .puzzle-block { background: #1e1e2e; }
body.dark-mode .puzzle-slot { background: #1a1a2e; }
body.dark-mode .fill-input { background: #252536; color: #ddd; border-color: #3d3d54; }
body.dark-mode .tf-statement { background: #252536; border-color: #3d3d54; }
body.dark-mode .glossary-input { background: #252536; color: #ddd; border-color: #3d3d54; }
body.dark-mode .enc-textarea { background: #252536; color: #ddd; border-color: #3d3d54; }
body.dark-mode .flow-tool { background: #1e1e2e; }
body.dark-mode .flashcard-front { background: linear-gradient(135deg, #2a1a2e, #1a1a3a); }
body.dark-mode .flashcard-back { background: linear-gradient(135deg, #1a2e1e, #0a2a1a); }

/* ═══════════════ BUANANET-STYLE LANDING PAGE ═══════════════ */
.bn-body {
    background: #0d1117;
    color: #c9d1d9;
    min-height: 100vh;
}
.bn-body .main-header {
    background: #161b22;
    border-bottom: 1px solid #30363d;
}

/* Navbar */
.bn-nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1100px;
    margin: 0 auto;
    width: 100%;
}
.bn-nav-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.05rem;
    color: #f0f6fc;
    text-decoration: none;
}
.bn-nav-logo img { height: 32px; }
.bn-nav-links {
    display: flex;
    gap: 20px;
    list-style: none;
}
.bn-nav-links a {
    color: #8b949e;
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    transition: color 0.2s;
}
.bn-nav-links a:hover { color: #f0f6fc; }
.bn-nav-btns {
    display: flex;
    gap: 8px;
}
.bn-btn-outline {
    background: transparent;
    color: #c9d1d9;
    border: 1px solid #30363d;
    padding: 6px 16px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.bn-btn-outline:hover { background: #21262d; border-color: #8b949e; }
.bn-btn-fill {
    background: #238636;
    color: #fff;
    border: 1px solid #2ea043;
    padding: 6px 16px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}
.bn-btn-fill:hover { background: #2ea043; }

/* Hero */
.bn-hero {
    text-align: center;
    padding: 60px 20px 40px;
    max-width: 800px;
    margin: 0 auto;
}
.bn-hero h1 {
    font-size: 2.2rem;
    font-weight: 700;
    color: #f0f6fc;
    line-height: 1.3;
    margin-bottom: 8px;
}
.bn-hero h1 strong { color: #58a6ff; }
.bn-hero-sub {
    font-size: 1.05rem;
    color: #8b949e;
    max-width: 550px;
    margin: 0 auto 24px;
    line-height: 1.6;
}
.bn-hero-btns {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}
.bn-hero-btns .bn-btn-fill {
    padding: 10px 28px;
    font-size: 0.95rem;
}
.bn-hero-btns .bn-btn-outline {
    padding: 10px 28px;
    font-size: 0.95rem;
}

/* Stats bar */
.bn-stats {
    display: flex;
    justify-content: center;
    gap: 32px;
    max-width: 600px;
    margin: 0 auto 32px;
    flex-wrap: wrap;
}
.bn-stat {
    text-align: center;
}
.bn-stat-num {
    font-size: 1.8rem;
    font-weight: 800;
    color: #58a6ff;
    display: block;
}
.bn-stat-label {
    font-size: 0.75rem;
    color: #8b949e;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Section header (☰ STYLE) */
.bn-section-hdr {
    max-width: 1100px;
    margin: 32px auto 16px;
    padding: 8px 20px;
    font-size: 0.8rem;
    font-weight: 700;
    color: #8b949e;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    border-bottom: 1px solid #21262d;
}
.bn-section-hdr::before {
    content: '☰ ';
}

/* 2-column cards grid */
.bn-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0;
    background: #21262d;
    border: 1px solid #21262d;
    border-radius: 6px;
    overflow: hidden;
}
.bn-card {
    background: #0d1117;
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    transition: background 0.15s;
    text-decoration: none;
    color: #c9d1d9;
}
.bn-card:hover { background: #161b22; }
.bn-card-icon { font-size: 1.4rem; width: 36px; text-align: center; flex-shrink: 0; }
.bn-card-info { flex: 1; min-width: 0; }
.bn-card-name { font-size: 0.9rem; font-weight: 600; color: #58a6ff; }
.bn-card-desc { font-size: 0.75rem; color: #8b949e; margin-top: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bn-card-badge {
    font-size: 0.65rem;
    background: #21262d;
    color: #8b949e;
    padding: 2px 8px;
    border-radius: 12px;
    white-space: nowrap;
    flex-shrink: 0;
}
.bn-card-lock { font-size: 0.8rem; flex-shrink: 0; }

/* Footer */
.bn-footer {
    max-width: 1100px;
    margin: 40px auto 0;
    padding: 20px;
    text-align: center;
    border-top: 1px solid #21262d;
    font-size: 0.75rem;
    color: #484f58;
    line-height: 1.8;
}
.bn-footer a { color: #58a6ff; text-decoration: none; }
.bn-footer a:hover { text-decoration: underline; }

/* Hide default header elements on landing */
.bn-body .btn-back,
.bn-body .btn-home,
.bn-body .btn-logout,
.bn-body #headerUser { display: none !important; }

/* Responsive */
@media (max-width: 768px) {
    .bn-grid { grid-template-columns: 1fr; }
    .bn-nav-links { display: none; }
    .bn-hero h1 { font-size: 1.5rem; }
    .bn-stats { gap: 16px; }
    .bn-stat-num { font-size: 1.4rem; }
    .bn-nav { padding: 0 8px; }
}
@media (max-width: 480px) {
    .bn-hero { padding: 40px 16px 24px; }
    .bn-card { padding: 12px 14px; }
    .bn-card-name { font-size: 0.82rem; }
}

/* ═══════════════ ROLE SELECTOR (Register) ═══════════════ */
.role-label {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px;
    border: 2px solid var(--gray-300);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    justify-content: center;
}
.role-label:has(input:checked) {
    border-color: var(--blue);
    background: var(--blue-light);
}

/* ══════════════════════════════════════════════════════════
   RESPONSIVE: MOBILE & TABLET OPTIMIZATION
   ══════════════════════════════════════════════════════════ */

/* ── Tablet (≤768px) ── */
@media (max-width: 768px) {

  /* --- HEADER --- */
  .main-header {
    padding: 10px 14px;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
    text-align: center;
  }
  .main-header h1 {
    font-size: 1rem;
    width: 100%;
    order: -1;
  }
  .header-sub {
    display: none;
  }
  .btn-back, .btn-home {
    padding: 6px 12px;
    font-size: 0.78rem;
    border-radius: 16px;
  }
  #headerUser { font-size: 0.75rem; }
  .btn-logout { padding: 6px 10px; font-size: 0.72rem; }

  /* --- MAIN CONTENT --- */
  main {
    padding: 14px 10px;
  }

  /* --- HOME --- */
  .home-title { font-size: 1.3rem; }
  .home-subtitle { font-size: 0.85rem; margin-bottom: 20px; }

  /* --- GRADE CARDS (Mapel & Kelas) --- */
  .grade-cards {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 12px;
    margin-bottom: 24px;
  }
  .grade-card {
    padding: 20px 14px;
  }
  .grade-card .grade-icon { font-size: 2.2rem; }
  .grade-card .grade-number { font-size: 1.5rem; }
  .grade-card .grade-desc { font-size: 0.78rem; }

  /* --- CHAPTER CARDS --- */
  .chapter-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .chapter-card {
    padding: 12px 14px;
  }
  .chapter-title { font-size: 0.88rem; }

  /* --- SECTION HEADER --- */
  .section-header h2 { font-size: 1.2rem; }

  /* --- CONTENT VIEW --- */
  .content-view {
    padding: 16px 14px;
    border-radius: var(--radius-sm);
  }
  .content-view h2 { font-size: 1.15rem; }
  .content-view h3 { font-size: 1rem; }
  .content-view p, .content-view li { font-size: 0.9rem; }
  .content-view ul, .content-view ol { margin-left: 16px; }

  /* --- TABS --- */
  .content-tabs { gap: 2px; }
  .content-tab {
    padding: 8px 12px;
    font-size: 0.8rem;
  }

  /* --- TABLES → horizontal scroll --- */
  table.simple-table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
    font-size: 0.8rem;
  }
  table.simple-table th,
  table.simple-table td {
    padding: 6px 8px;
  }

  /* --- QUIZ --- */
  .quiz-question {
    padding: 16px 12px;
  }
  .quiz-question h3 { font-size: 0.95rem; }
  .quiz-option {
    padding: 12px 14px;
    font-size: 0.88rem;
  }
  .quiz-score .score-circle {
    width: 100px;
    height: 100px;
    font-size: 2rem;
  }

  /* --- BUTTONS --- */
  .btn {
    padding: 8px 18px;
    font-size: 0.82rem;
  }
  .btn-sm { padding: 5px 10px; font-size: 0.75rem; }

  /* --- DRAG & DROP --- */
  .dd-container {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .dd-item { font-size: 0.82rem; padding: 8px 10px; }
  .dd-draggable { min-height: 40px; display: flex; align-items: center; justify-content: center; }

  /* --- SIMULATION --- */
  .sim-container {
    padding: 16px 12px;
  }
  .sim-input {
    width: 100%;
    font-size: 0.9rem;
  }
  .sim-row { flex-direction: column; align-items: stretch; }
  .sim-row label { min-width: auto; }

  /* --- LOGIC GATES --- */
  .gate-grid {
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 8px;
  }
  .gate-card { padding: 10px; }

  /* --- ENCRYPTION --- */
  .enc-io {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .enc-textarea { height: 80px; font-size: 0.85rem; }

  /* --- FLASHCARDS --- */
  .flashcard-wrapper {
    height: 200px;
    max-width: 100%;
  }
  .flashcard-text { font-size: 1rem; }
  .flashcard-front, .flashcard-back { padding: 16px; }

  /* --- TRUE / FALSE --- */
  .tf-statement { font-size: 0.95rem; padding: 14px; }
  .btn-tf {
    padding: 12px 24px;
    font-size: 1rem;
    min-width: 110px;
  }

  /* --- FILL IN THE BLANK --- */
  .fill-input {
    font-size: 1rem;
    padding: 12px 14px;
  }

  /* --- CODE PUZZLE --- */
  .puzzle-slot { font-size: 0.8rem; padding: 8px 10px; min-height: 36px; }
  .puzzle-block { font-size: 0.78rem; padding: 6px 12px; }

  /* --- CROSSWORD --- */
  .cw-cell { font-size: 0.8rem; }
  .cw-clue { font-size: 0.78rem; }

  /* --- NETWORK SIM --- */
  .network-canvas { height: 180px; }
  .net-node { min-width: 70px; padding: 8px; font-size: 0.75rem; }
  .net-icon { font-size: 1.3rem; }

  /* --- FLOWCHART --- */
  .flow-canvas { height: 300px; }
  .flow-tool {
    padding: 6px 8px;
    font-size: 0.62rem;
    min-width: 48px;
  }

  /* --- GLOSSARY --- */
  .glossary-input {
    font-size: 0.85rem;
    padding: 10px 14px;
    max-width: 100%;
  }
  .glossary-alpha {
    flex-wrap: wrap;
    gap: 1px;
  }
  .glossary-letter {
    width: 22px;
    height: 22px;
    line-height: 22px;
    font-size: 0.7rem;
  }
  .glossary-term { padding: 8px 10px; }
  .glossary-term-name { font-size: 0.82rem; }
  .glossary-term-def { font-size: 0.78rem; }

  /* --- PROGRESS --- */
  .progress-stat-num { font-size: 1.6rem; }
  .progress-stat { padding: 14px 10px; }

  /* --- FOOTER --- */
  .main-footer {
    padding: 10px 8px;
    font-size: 0.7rem;
    line-height: 1.4;
  }

  /* --- FLEX CENTER utility --- */
  .flex-center { gap: 6px; }
}

/* ── Small Phone (≤480px) ── */
@media (max-width: 480px) {

  /* --- HEADER --- */
  .main-header {
    padding: 8px 8px;
    gap: 4px;
  }
  .main-header h1 {
    font-size: 0.9rem;
  }
  .btn-back, .btn-home {
    padding: 5px 10px;
    font-size: 0.72rem;
    border-radius: 14px;
  }
  #headerUser { font-size: 0.7rem; }
  .btn-logout { padding: 5px 8px; font-size: 0.68rem; }
  .btn-dark-toggle {
    width: 32px;
    height: 32px;
    font-size: 0.9rem;
  }

  /* --- MAIN --- */
  main { padding: 10px 6px; }

  /* --- HOME --- */
  .home-title { font-size: 1.15rem; }
  .home-subtitle { font-size: 0.78rem; }

  /* --- GRADE CARDS --- */
  .grade-cards {
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 8px;
  }
  .grade-card {
    padding: 14px 10px;
  }
  .grade-card .grade-icon { font-size: 1.8rem; }
  .grade-card .grade-number { font-size: 1.2rem; }
  .grade-card .grade-desc { font-size: 0.72rem; }

  /* --- SUBJECT CARDS (home page) --- */
  .subject-card .grade-number { font-size: 0.82rem !important; }

  /* --- CHAPTER CARDS --- */
  .chapter-card {
    padding: 10px;
    gap: 6px;
  }
  .chapter-title { font-size: 0.82rem; }
  .chapter-num { font-size: 0.95rem; min-width: 26px; }

  /* --- QUIZ --- */
  .quiz-option {
    padding: 10px 12px;
    font-size: 0.82rem;
  }
  .quiz-score .score-circle {
    width: 80px;
    height: 80px;
    font-size: 1.5rem;
  }

  /* --- BUTTONS --- */
  .btn {
    padding: 7px 14px;
    font-size: 0.78rem;
    border-radius: 20px;
  }
  .btn-sm { padding: 4px 8px; font-size: 0.7rem; }

  /* --- TABS --- */
  .content-tab {
    padding: 6px 8px;
    font-size: 0.72rem;
  }

  /* --- FLASHCARDS --- */
  .flashcard-wrapper { height: 170px; }
  .flashcard-text { font-size: 0.88rem; }

  /* --- TRUE/FALSE --- */
  .btn-tf {
    padding: 10px 20px;
    font-size: 0.9rem;
    min-width: 90px;
  }

  /* --- LOGIC GATES --- */
  .gate-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* --- NETWORK SIM --- */
  .network-canvas { height: 150px; }
  .net-node { min-width: 55px; padding: 6px; font-size: 0.65rem; }
  .net-icon { font-size: 1.1rem; }

  /* --- FLOWCHART --- */
  .flow-canvas { height: 250px; }
  .flow-tool {
    padding: 4px 6px;
    font-size: 0.58rem;
    min-width: 40px;
  }

  /* --- CROSSWORD --- */
  .cw-cell { font-size: 0.7rem; }

  /* --- GLOSSARY --- */
  .glossary-letter {
    width: 20px;
    height: 20px;
    line-height: 20px;
    font-size: 0.65rem;
  }

  /* --- PROGRESS --- */
  .progress-stat-num { font-size: 1.3rem; }

  /* --- INFO BOX --- */
  .info-box, .activity-box {
    padding: 8px 10px;
    font-size: 0.82rem;
  }

  /* --- LANDING --- */
  .landing-hero { padding: 24px 14px; }
  .landing-icon { font-size: 3rem; }
  .landing-title { font-size: 1.4rem; }
  .landing-subtitle { font-size: 0.82rem; }
  .landing-stats { grid-template-columns: repeat(2, 1fr); }
  .landing-stat-num { font-size: 1.5rem; }
  .landing-benefits { grid-template-columns: 1fr; }
  .landing-features { grid-template-columns: repeat(2, 1fr); }
  .landing-feature { font-size: 0.75rem; padding: 10px; }
  .btn-lg { padding: 12px 24px !important; font-size: 0.95rem !important; }
}