/* ============================================================
   NET-QUIZ // 1960s RETRO PROFESSIONAL THEME
   Warm parchment · Earthy greens · Burnt orange · Easy on eyes
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;700;900&family=Special+Elite&family=Courier+Prime:wght@400;700&family=Oswald:wght@400;500;700&display=swap');

:root {
    /* 60s Colour Palette — warm, muted, retro */
    --clr-bg: #f5ede0;
    /* warm parchment */
    --clr-bg-panel: #efe4d1;
    /* slightly darker parchment */
    --clr-bg-card: #faf4ea;
    /* light cream card */
    --clr-ink: #2c1f0e;
    /* deep brown ink */
    --clr-ink-soft: #5a4230;
    /* mid brown */
    --clr-ink-muted: #8a6e52;
    /* muted tan */

    --clr-primary: #c45c1a;
    /* burnt orange */
    --clr-primary-dim: #a04a14;
    --clr-primary-bg: rgba(196, 92, 26, 0.08);

    --clr-green: #3a6b45;
    /* muted forest green */
    --clr-green-dim: #2e5437;
    --clr-green-bg: rgba(58, 107, 69, 0.10);

    --clr-gold: #c8960a;
    /* warm gold */
    --clr-gold-dim: #a07a08;

    --clr-red: #b5372a;
    /* deep terracotta red */
    --clr-red-bg: rgba(181, 55, 42, 0.10);

    --clr-border: #d4b896;
    --clr-border-dark: #b8966e;

    --clr-shadow: rgba(44, 31, 14, 0.12);

    /* Fonts */
    --font-body: 'Courier Prime', 'Courier New', monospace;
    --font-display: 'Oswald', sans-serif;
    --font-serif: 'Playfair Display', Georgia, serif;
    --font-type: 'Special Elite', 'Courier New', monospace;

    --radius-sm: 3px;
    --radius: 6px;
    --radius-lg: 10px;
}

/* ============ RESET ============ */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* ============ BODY ============ */
body {
    background-color: var(--clr-bg);
    background-image:
        repeating-linear-gradient(0deg,
            transparent,
            transparent 28px,
            rgba(180, 140, 90, 0.07) 28px,
            rgba(180, 140, 90, 0.07) 29px);
    color: var(--clr-ink);
    font-family: var(--font-body);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Subtle paper texture overlay */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
    pointer-events: none;
    z-index: 0;
    opacity: 1;
}

/* Remove old CRT elements */
.scanlines,
.crt-vignette,
.noise,
#grid-canvas {
    display: none !important;
}

/* ============ LAYOUT ============ */
#app-container {
    max-width: 720px;
    margin: 0 auto;
    padding: 20px 20px 60px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 10;
}

/* ============ HEADER ============ */
#main-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 10px 0 12px;
    border-bottom: 3px double var(--clr-border-dark);
    margin-bottom: 20px;
    gap: 12px;
    flex-wrap: wrap;
}

.logo-block {
    display: flex;
    align-items: baseline;
    gap: 2px;
    line-height: 1;
}

.logo-bracket {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 400;
    color: var(--clr-gold-dim);
    opacity: 0.7;
}

.logo-text {
    font-family: var(--font-serif);
    font-size: 2.4rem;
    font-weight: 900;
    letter-spacing: -0.5px;
    line-height: 1.5;
    /* warm gradient: deep amber → burnt orange */
    background: linear-gradient(135deg,
            #8b4e0a 0%,
            #c45c1a 40%,
            #e07a30 70%,
            #a04010 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    /* subtle ink press shadow */
    filter: drop-shadow(1px 2px 0px rgba(100, 40, 0, 0.25));
    position: relative;
}

.logo-sub {
    font-family: var(--font-display);
    font-size: 0.68rem;
    color: var(--clr-ink-muted);
    margin-top: 1px;
    letter-spacing: 1px;
    text-transform: uppercase;
    /* thin decorative rule above */
    border-top: 1px solid var(--clr-border);
    padding-top: 1px;
}

.header-right {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 6px;
}

.sys-status {
    display: flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-display);
    font-size: 0.68rem;
    color: var(--clr-green);
    letter-spacing: 3px;
    text-transform: uppercase;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--clr-green);
    animation: statusPulse 2s ease-in-out infinite;
}

@keyframes statusPulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.35;
    }
}

/* ============ PROGRESS BAR ============ */
#progress-container {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 140px;

}

.progress-bar {
    flex: 1;
    height: 6px;
    background: var(--clr-border);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--clr-green-dim), var(--clr-green));
    width: 0%;
    transition: width 0.4s ease;
    border-radius: 3px;
}

.progress-text {
    font-family: var(--font-display);
    font-size: 0.72rem;
    color: var(--clr-gold);
    white-space: nowrap;
    letter-spacing: 1px;
}

/* ============ UTILITY ============ */
.hidden {
    display: none !important;
}

.view {
    flex: 1;
    display: flex;
    flex-direction: column;
    animation: fadeUp 0.35s ease both;
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(14px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============ TERMINAL PROMPT ============ */
.terminal-prompt {
    font-family: var(--font-type);
    font-size: 0.82rem;
    color: var(--clr-ink-soft);
    margin-bottom: 18px;
    letter-spacing: 0.5px;
    padding: 10px 16px;
    background: var(--clr-bg-panel);
    border: 1px solid var(--clr-border);
    border-left: 4px solid var(--clr-primary);
    border-radius: var(--radius-sm);
}

.prompt-prefix {
    color: var(--clr-primary);
    font-weight: 700;
}

.prompt-cmd {
    color: var(--clr-green);
}

.cursor-blink {
    display: inline-block;
    animation: blink 1s step-end infinite;
    color: var(--clr-primary);
}

@keyframes blink {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0;
    }
}

/* ============ STATS BAR ============ */
.stats-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 10px 16px;
    background: var(--clr-bg-panel);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-sm);
    margin-bottom: 22px;
    font-family: var(--font-display);
    font-size: 0.72rem;
    color: var(--clr-ink-muted);
    letter-spacing: 1.5px;
    text-transform: uppercase;
    flex-wrap: wrap;
    box-shadow: 0 1px 4px var(--clr-shadow);
}

.stat-item {
    color: var(--clr-ink-soft);
}

.stat-item span {
    color: var(--clr-primary);
    font-weight: 700;
}

.stat-sep {
    color: var(--clr-border-dark);
}

/* ============ CHAPTER GRID ============ */
.chapter-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
}

.chapter-card {
    background: var(--clr-bg-card);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius);
    padding: 16px 20px;
    cursor: pointer;
    transition: all 0.18s ease;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 6px var(--clr-shadow);
}

.chapter-card::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--clr-primary);
    transition: width 0.2s ease;
}

.chapter-card:hover {
    border-color: var(--clr-primary);
    box-shadow: 0 4px 16px var(--clr-shadow);
    transform: translateX(4px);
    background: #fff9f2;
}

.chapter-card:hover::before {
    width: 6px;
}

.chapter-card:active {
    transform: translateX(6px) scale(0.99);
    box-shadow: 0 1px 4px var(--clr-shadow);
}

.chapter-card .card-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.chapter-card h3 {
    font-family: var(--font-body);
    font-size: 0.88rem;
    color: var(--clr-ink);
    font-weight: 700;
    letter-spacing: 0.3px;
    line-height: 1.35;
}

.chapter-card .card-meta {
    font-size: 0.68rem;
    color: var(--clr-ink-muted);
    font-family: var(--font-display);
    letter-spacing: 2px;
    text-transform: uppercase;
}

.chapter-progress {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
    flex-shrink: 0;
    margin-left: 14px;
}

.chapter-progress .prog-count {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--clr-gold);
    line-height: 1;
}

.chapter-progress .prog-bar-mini {
    width: 60px;
    height: 4px;
    background: var(--clr-border);
    border-radius: 2px;
    overflow: hidden;
}

.chapter-progress .prog-fill-mini {
    height: 100%;
    background: var(--clr-green);
    transition: width 0.4s ease;
}

.chapter-progress.complete .prog-count {
    color: var(--clr-green);
}

/* ============ QUIZ HEADER BAR ============ */
.quiz-header-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 18px;
}

.chapter-badge {
    font-family: var(--font-display);
    font-size: 0.7rem;
    color: var(--clr-green);
    background: var(--clr-green-bg);
    border: 1px solid var(--clr-green-dim);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    letter-spacing: 3px;
    text-transform: uppercase;
}

/* ============ QUESTION CARD ============ */
.question-card {
    background: var(--clr-bg-card);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius);
    padding: 26px 22px;
    margin-bottom: 16px;
    position: relative;
    box-shadow: 0 2px 8px var(--clr-shadow);
}

.question-card::after {
    content: '🕊️';
    position: absolute;
    top: 14px;
    right: 18px;
    font-size: 0.7rem;
    color: var(--clr-border-dark);
}

.question-id {
    font-family: var(--font-display);
    font-size: 0.65rem;
    color: var(--clr-gold);
    letter-spacing: 3px;
    margin-bottom: 14px;
    text-transform: uppercase;
}

.question-text {
    font-family: var(--font-body);
    font-size: 1.02rem;
    line-height: 1.7;
    color: var(--clr-ink);
    margin-bottom: 24px;
    font-weight: 400;
    user-select: none;
    -webkit-user-select: none;
}

/* ============ OPTIONS ============ */
.options-container {
    display: flex;
    flex-direction: column;
    gap: 9px;
}

.option-btn {
    background: var(--clr-bg-panel);
    border: 1px solid var(--clr-border);
    border-radius: var(--radius-sm);
    padding: 13px 16px;
    font-family: var(--font-body);
    font-size: 0.9rem;
    color: var(--clr-ink-soft);
    text-align: left;
    cursor: pointer;
    transition: all 0.15s ease;
    line-height: 1.45;
    position: relative;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    box-shadow: 0 1px 3px var(--clr-shadow);
}

.option-btn .opt-key {
    color: var(--clr-gold);
    font-size: 0.82rem;
    font-weight: 700;
    min-width: 20px;
    flex-shrink: 0;
    font-family: var(--font-display);
}

.option-btn:hover:not(:disabled) {
    border-color: var(--clr-primary);
    color: var(--clr-ink);
    background: #fff8f0;
    box-shadow: 0 2px 10px rgba(196, 92, 26, 0.12);
    transform: translateX(4px);
}

.option-btn:active:not(:disabled) {
    transform: translateX(6px);
}

.option-btn.correct {
    border-color: var(--clr-green) !important;
    color: var(--clr-green-dim) !important;
    background: var(--clr-green-bg) !important;
    box-shadow: 0 0 0 2px rgba(58, 107, 69, 0.2) !important;
    animation: correctPulse 0.45s ease;
}

.option-btn.correct .opt-key {
    color: var(--clr-green);
}

.option-btn.wrong {
    border-color: var(--clr-red) !important;
    color: var(--clr-red) !important;
    background: var(--clr-red-bg) !important;
    box-shadow: 0 0 0 2px rgba(181, 55, 42, 0.15) !important;
    animation: wrongShake 0.4s ease;
}

.option-btn.wrong .opt-key {
    color: var(--clr-red);
}

@keyframes correctPulse {
    0% {
        transform: scale(1);
    }

    30% {
        transform: scale(1.015) translateX(4px);
    }

    100% {
        transform: scale(1) translateX(4px);
    }
}

@keyframes wrongShake {

    0%,
    100% {
        transform: translateX(4px);
    }

    20% {
        transform: translateX(9px);
    }

    40% {
        transform: translateX(0px);
    }

    60% {
        transform: translateX(7px);
    }

    80% {
        transform: translateX(2px);
    }
}

/* ============ NEXT BUTTON ============ */
#next-btn {
    margin-top: 8px;
    animation: fadeUp 0.2s ease both;
}

/* ============ EXPLANATION BOX ============ */
.explanation-box {
    background: rgba(58, 107, 69, 0.07);
    border: 1px solid var(--clr-green-dim);
    border-left: 4px solid var(--clr-green);
    border-radius: var(--radius);
    padding: 14px 16px;
    margin-bottom: 16px;
    font-family: var(--font-body);
    font-size: 0.85rem;
    color: var(--clr-ink-soft);
    line-height: 1.65;
    animation: fadeUp 0.3s ease both;
}

.exp-label {
    color: var(--clr-green);
    display: block;
    margin-bottom: 6px;
    font-size: 0.68rem;
    letter-spacing: 3px;
    font-family: var(--font-display);
    text-transform: uppercase;
    font-weight: 700;
}

/* ============ BUTTONS ============ */
.retro-btn {
    font-family: var(--font-display);
    font-size: 0.8rem;
    padding: 12px 22px;
    border: 2px solid;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.15s ease;
    letter-spacing: 2px;
    background: transparent;
    text-transform: uppercase;
    font-weight: 500;
}

.retro-btn.primary {
    border-color: var(--clr-primary);
    color: var(--clr-primary);
    background: var(--clr-primary-bg);
}

.retro-btn.primary:hover {
    background: var(--clr-primary);
    color: #fff9f2;
    box-shadow: 0 4px 14px rgba(196, 92, 26, 0.25);
    transform: translateY(-2px);
}

.retro-btn.secondary {
    border-color: var(--clr-border-dark);
    color: var(--clr-ink-soft);
    background: transparent;
}

.retro-btn.secondary:hover {
    background: var(--clr-bg-panel);
    border-color: var(--clr-ink-soft);
    box-shadow: 0 3px 10px var(--clr-shadow);
    transform: translateY(-2px);
}

.retro-btn:active {
    transform: translateY(0) !important;
    opacity: 0.85;
}

.retro-btn.small {
    padding: 8px 14px;
    font-size: 0.72rem;
}

.retro-btn.large {
    width: 100%;
    padding: 16px;
    font-size: 0.85rem;
}

/* ============ RESULTS VIEW ============ */
.results-card {
    background: var(--clr-bg-card);
    border: 1px solid var(--clr-border);
    border-top: 4px solid var(--clr-primary);
    border-radius: var(--radius-lg);
    padding: 36px 26px;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 18px;
    box-shadow: 0 4px 20px var(--clr-shadow);
}

.results-ascii pre {
    font-family: var(--font-type);
    font-size: 0.68rem;
    color: var(--clr-primary);
    line-height: 1.4;
    letter-spacing: 1px;
}

.score-display {
    font-family: var(--font-serif);
    font-size: 5rem;
    color: var(--clr-ink);
    line-height: 1;
    font-weight: 900;
}

.score-divider {
    color: var(--clr-border-dark);
    font-size: 4rem;
}

.score-percent {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--clr-primary);
    letter-spacing: 4px;
    font-weight: 700;
}

.score-grade {
    font-family: var(--font-display);
    font-size: 0.85rem;
    letter-spacing: 3px;
    padding: 6px 18px;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    font-weight: 500;
}

.score-grade.grade-s {
    color: var(--clr-green);
    border: 2px solid var(--clr-green);
    background: var(--clr-green-bg);
}

.score-grade.grade-a {
    color: var(--clr-green-dim);
    border: 2px solid var(--clr-green-dim);
}

.score-grade.grade-b {
    color: var(--clr-gold);
    border: 2px solid var(--clr-gold);
}

.score-grade.grade-c {
    color: var(--clr-red);
    border: 2px solid var(--clr-red);
}

.results-subtitle {
    font-family: var(--font-display);
    font-size: 0.7rem;
    color: var(--clr-ink-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
}

.results-actions {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 100%;
}

/* ============ FLASHCARD ============ */
.flashcard-container {
    perspective: 1200px;
    margin-bottom: 20px;
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 300px;
}

.flashcard {
    background-color: transparent;
    width: 100%;
    flex: 1;
    cursor: pointer;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    min-height: 300px;
    display: grid;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.4, 0.2, 0.2, 1);
    transform-style: preserve-3d;
}

.flashcard.flipped .flashcard-inner {
    transform: rotateY(180deg);
}

.flashcard-front,
.flashcard-back {
    grid-area: 1 / 1;
    width: 100%;
    min-height: 300px;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: var(--radius-lg);
    padding: 36px 24px 60px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 16px;
    position: relative;
    box-shadow: 0 4px 16px var(--clr-shadow);
}

.flashcard-front {
    background: var(--clr-bg-card);
    border: 1px solid var(--clr-border);
    border-top: 4px solid var(--clr-gold);
}

.flashcard-back {
    background: #2c1f0e;
    border: 1px solid var(--clr-ink);
    border-top: 4px solid var(--clr-primary);
    transform: rotateY(180deg);
}

.fc-label {
    font-family: var(--font-display);
    font-size: 0.65rem;
    letter-spacing: 4px;
    margin-bottom: 4px;
    text-transform: uppercase;
    font-weight: 700;
}

.flashcard-front .fc-label {
    color: var(--clr-gold);
}

.flashcard-back .fc-label {
    color: var(--clr-primary);
}

.flashcard-front .question-text {
    font-size: 1rem;
    color: var(--clr-ink);
    margin-bottom: 0;
}

.answer-text {
    font-family: var(--font-body);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--clr-bg);
    line-height: 1.5;
}

.flip-hint {
    position: absolute;
    bottom: 16px;
    font-family: var(--font-display);
    font-size: 0.62rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    animation: blink 1.8s ease-in-out infinite;
}

.flashcard-front .flip-hint {
    color: var(--clr-ink-muted);
}

.flashcard-back .flip-hint {
    color: rgba(245, 237, 224, 0.4);
}

.fc-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    margin-top: 8px;
}

.fc-progress {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--clr-gold);
    letter-spacing: 2px;
}

/* ============ TRANSLATION BOX ============ */
.translation-box {
    width: 100%;
    padding: 12px 16px;
    background: rgba(200, 150, 10, 0.07);
    border: 1px solid var(--clr-gold-dim);
    border-left: 3px solid var(--clr-gold);
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.92rem;
    color: var(--clr-ink-soft);
    direction: rtl;
    text-align: right;
    line-height: 1.6;
    animation: fadeUp 0.3s ease both;
    margin-bottom: 16px;
}

/* ============ SCROLLBAR ============ */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--clr-bg-panel);
}

::-webkit-scrollbar-thumb {
    background: var(--clr-border-dark);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--clr-ink-muted);
}

/* ============ RESPONSIVE ============ */
@media (max-width: 480px) {
    .logo-block {
        font-size: 1.7rem;
    }

    .question-text {
        font-size: 0.93rem;
    }

    .option-btn {
        font-size: 0.84rem;
        padding: 12px 13px;
    }

    .score-display {
        font-size: 3.8rem;
    }

    .stats-bar {
        font-size: 0.68rem;
        gap: 10px;
    }
}

/* ============ FOOTER ============ */
#main-footer {
    margin-top: 40px;
    padding: 18px 0 24px;
    border-top: 2px double var(--clr-border-dark);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.footer-links {
    display: flex;
    gap: 14px;
}

.footer-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-display);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    text-decoration: none;
    padding: 7px 16px;
    border: 1px solid;
    border-radius: var(--radius-sm);
    transition: all 0.18s ease;
}

.footer-link--tg {
    color: #1a78a0;
    border-color: #aaccdd;
    background: rgba(26, 120, 160, 0.06);
}

.footer-link--tg:hover {
    background: #1a78a0;
    color: #fff;
    box-shadow: 0 3px 10px rgba(26, 120, 160, 0.25);
    transform: translateY(-2px);
}

.footer-link--wa {
    color: #2a7a3e;
    border-color: #a8d4b0;
    background: rgba(42, 122, 62, 0.06);
}

.footer-link--wa:hover {
    background: #2a7a3e;
    color: #fff;
    box-shadow: 0 3px 10px rgba(42, 122, 62, 0.25);
    transform: translateY(-2px);
}

.footer-copy {
    font-family: var(--font-display);
    font-size: 0.65rem;
    letter-spacing: 2px;
    color: var(--clr-ink-muted);
    text-transform: uppercase;
}