/* =====================================================================
   Flashcards — Susic Security
   Design system mirrored from susic-security.com
   ===================================================================== */

:root {
    /* Primary palette */
    --primary-400: #29b6f6;
    --primary-500: #03a9f4;
    --primary-600: #039be5;
    --primary-700: #0288d1;

    /* Accents */
    --accent-cyan: #00d4ff;
    --accent-blue: #0099ff;
    --success: #22c55e;
    --success-glow: rgba(34, 197, 94, 0.35);
    --danger: #f43f6e;
    --danger-glow: rgba(244, 63, 110, 0.35);

    /* Dark theme (default) */
    --bg-primary: #0a0a0a;
    --bg-secondary: #111111;
    --bg-tertiary: #1a1a1a;
    --bg-glass: rgba(255, 255, 255, 0.05);
    --bg-glass-hover: rgba(255, 255, 255, 0.08);
    --bg-code: rgba(0, 0, 0, 0.35);

    --text-primary: #ffffff;
    --text-secondary: #e0e0e0;
    --text-muted: #b0b0b0;

    --border-color: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(255, 255, 255, 0.2);

    --gradient-primary: linear-gradient(135deg, var(--primary-600), var(--primary-400));
    --gradient-secondary: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
    --gradient-bg: linear-gradient(135deg, var(--bg-primary), var(--bg-secondary), var(--bg-tertiary));

    --glow-primary: 0 0 20px rgba(3, 169, 244, 0.3);
    --glow-accent: 0 0 24px rgba(0, 212, 255, 0.4);

    --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --easing-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    --font-mono: 'JetBrains Mono', 'Fira Code', ui-monospace, monospace;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    --blur-md: blur(12px);

    --nav-h: 68px;
}

body.light-theme {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --bg-glass: rgba(255, 255, 255, 0.9);
    --bg-glass-hover: rgba(255, 255, 255, 0.98);
    --bg-code: rgba(15, 23, 42, 0.05);

    --text-primary: #1a1a1a;
    --text-secondary: #374151;
    --text-muted: #6b7280;

    --border-color: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 0, 0, 0.16);

    --gradient-primary: linear-gradient(135deg, #60a5fa, #93c5fd);
    --gradient-secondary: linear-gradient(135deg, #0ea5e9, #6366f1);
    --gradient-bg: linear-gradient(135deg, #f8fafc, #f1f5f9, #e2e8f0);

    --glow-primary: 0 0 20px rgba(59, 130, 246, 0.35);
    --glow-accent: 0 0 24px rgba(14, 165, 233, 0.3);
}

/* ---------- Reset & base ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--gradient-bg);
    background-attachment: fixed;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: color 0.4s ease, background 0.4s ease;
}

::selection { background: rgba(3, 169, 244, 0.3); color: #fff; }

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--primary-600); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--primary-500); }

.mono { font-family: var(--font-mono); font-size: 0.9em; color: var(--primary-400); }
.muted { color: var(--text-muted); }

/* ---------- Background FX ---------- */
#bg-canvas { position: fixed; inset: 0; width: 100%; height: 100%; z-index: -2; opacity: 0.85; }
.bg-gradient {
    position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background:
        radial-gradient(60% 55% at 15% 12%, rgba(3, 169, 244, 0.14), transparent 60%),
        radial-gradient(55% 55% at 88% 20%, rgba(0, 212, 255, 0.12), transparent 60%),
        radial-gradient(60% 60% at 50% 100%, rgba(2, 136, 209, 0.10), transparent 60%);
}
body.light-theme .bg-gradient {
    background:
        radial-gradient(60% 55% at 15% 12%, rgba(59, 130, 246, 0.12), transparent 60%),
        radial-gradient(55% 55% at 88% 20%, rgba(99, 102, 241, 0.10), transparent 60%);
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 1.5rem; width: 100%; }

/* ---------- Glass utility ---------- */
.glassmorphism, .glass-card {
    background: var(--bg-glass);
    backdrop-filter: var(--blur-md);
    -webkit-backdrop-filter: var(--blur-md);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
}

/* ---------- Navbar ---------- */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    height: var(--nav-h);
    border-radius: 0;
    border-left: 0; border-right: 0; border-top: 0;
}
.nav-content { height: 100%; display: flex; align-items: center; justify-content: space-between; }
.logo-link { display: flex; align-items: center; gap: 0.6rem; font-weight: 800; font-size: 1.15rem; letter-spacing: -0.02em; }
.logo-mark { display: grid; place-items: center; filter: drop-shadow(var(--glow-accent)); }
.logo-text { color: var(--text-primary); }
.nav-right { display: flex; align-items: center; gap: 1.25rem; }
.nav-link { font-size: 0.9rem; font-weight: 500; color: var(--text-muted); font-family: var(--font-mono); }
.nav-link:hover { color: var(--primary-400); }

.theme-toggle {
    display: grid; place-items: center;
    width: 40px; height: 40px; border-radius: var(--radius-full);
    background: var(--bg-glass); border: 1px solid var(--border-color);
    color: var(--text-secondary);
}
.theme-toggle:hover { border-color: var(--border-hover); color: var(--primary-400); transform: translateY(-1px); }
.theme-toggle .icon-sun { display: none; }
body.light-theme .theme-toggle .icon-sun { display: block; }
body.light-theme .theme-toggle .icon-moon { display: none; }

/* ---------- Layout ---------- */
.main { padding-top: calc(var(--nav-h) + 3rem); padding-bottom: 3rem; min-height: 100vh; }
.view { animation: fadeUp 0.5s ease both; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: translateY(0); } }

/* ---------- Section header ---------- */
.section-header { text-align: center; margin-bottom: 2.5rem; }
.section-badge {
    display: inline-flex; align-items: center; gap: 0.5rem;
    padding: 0.35rem 0.9rem; margin-bottom: 1.25rem;
    background: var(--bg-glass); border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 0.8rem; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase;
    color: var(--primary-400); font-family: var(--font-mono);
}
.badge-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent-cyan); box-shadow: 0 0 10px var(--accent-cyan); animation: pulse 2s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.4; } }

.section-title {
    font-size: clamp(2rem, 5vw, 3rem); font-weight: 800; line-height: 1.15; letter-spacing: -0.02em;
    margin-bottom: 0.85rem;
    background: linear-gradient(135deg, var(--text-primary), var(--primary-400));
    background-clip: text; -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.title-accent {
    background: var(--gradient-secondary);
    background-clip: text; -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.section-subtitle { color: var(--text-muted); font-size: 1.08rem; max-width: 620px; margin: 0 auto; }

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 0.55rem;
    padding: 0.85rem 1.6rem; font-weight: 600; font-size: 0.95rem; font-family: inherit;
    border-radius: var(--radius-lg); border: none; cursor: pointer;
    position: relative; overflow: hidden; transition: var(--transition-normal); color: #fff;
}
.btn::before {
    content: ''; position: absolute; inset: 0; left: -100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.22), transparent);
    transition: left 0.5s;
}
.btn:hover::before { left: 100%; }
.btn:focus-visible { outline: 2px solid var(--primary-400); outline-offset: 2px; }
.btn-primary { background: var(--gradient-primary); color: #fff; box-shadow: var(--glow-primary); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(3,169,244,0.4); }
.btn-secondary { background: var(--bg-glass); color: var(--text-primary); border: 1px solid var(--border-color); }
.btn-secondary:hover { background: var(--bg-glass-hover); border-color: var(--border-hover); transform: translateY(-2px); }
body.light-theme .btn-primary { color: #0b2540; }

.btn-link {
    background: none; border: none; cursor: pointer;
    color: var(--primary-400); font-family: var(--font-mono); font-size: 0.88rem; font-weight: 500;
    padding: 0.25rem 0; transition: var(--transition-fast);
}
.btn-link:hover { color: var(--accent-cyan); }

/* ---------- Upload view ---------- */
.upload-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: 1.5rem; align-items: stretch; }
.glass-card { padding: 2rem; }

.dropzone {
    display: grid; place-items: center; text-align: center; cursor: pointer; min-height: 340px;
    border-style: dashed; border-width: 2px; transition: var(--transition-normal);
}
.dropzone:hover, .dropzone:focus-visible { border-color: var(--primary-500); background: var(--bg-glass-hover); transform: translateY(-2px); box-shadow: var(--glow-primary); outline: none; }
.dropzone.dragover { border-color: var(--accent-cyan); background: rgba(0, 212, 255, 0.06); box-shadow: var(--glow-accent); transform: scale(1.01); }
.dropzone-inner { display: flex; flex-direction: column; align-items: center; gap: 0.6rem; }
.dropzone-icon { color: var(--primary-400); margin-bottom: 0.4rem; filter: drop-shadow(var(--glow-primary)); }
.dropzone h3 { font-size: 1.25rem; font-weight: 700; }
.dropzone .btn-primary { margin-top: 0.9rem; }
.dropzone .btn-link { margin-top: 0.5rem; }

.format-card { display: flex; flex-direction: column; gap: 0.85rem; }
.format-title { display: flex; align-items: center; gap: 0.5rem; font-size: 1.1rem; font-weight: 700; color: var(--text-primary); }
.format-title svg { color: var(--primary-400); }
.code-block {
    background: var(--bg-code); border: 1px solid var(--border-color); border-radius: var(--radius-lg);
    padding: 1rem 1.1rem; overflow-x: auto; font-family: var(--font-mono); font-size: 0.82rem;
    line-height: 1.55; color: var(--text-secondary); white-space: pre;
}
.code-block code { font-family: inherit; }

.parse-error {
    margin-top: 1.5rem; text-align: center; color: var(--danger);
    background: rgba(244, 63, 110, 0.08); border: 1px solid rgba(244, 63, 110, 0.3);
    border-radius: var(--radius-lg); padding: 0.85rem 1rem; font-size: 0.92rem;
}

/* ---------- Study view ---------- */
.view-study { max-width: 760px; }
.study-top { display: flex; flex-direction: column; gap: 1rem; margin-bottom: 1.75rem; }
.progress-wrap { display: flex; flex-direction: column; gap: 0.5rem; }
.progress-bar { height: 8px; background: var(--bg-glass); border: 1px solid var(--border-color); border-radius: var(--radius-full); overflow: hidden; }
.progress-fill { height: 100%; width: 0%; background: var(--gradient-secondary); border-radius: var(--radius-full); box-shadow: var(--glow-accent); transition: width 0.45s var(--easing-bounce); }
.progress-label { display: flex; justify-content: space-between; font-size: 0.82rem; color: var(--text-muted); font-family: var(--font-mono); }

.stat-chips { display: flex; gap: 0.75rem; }
.chip {
    flex: 1; display: flex; flex-direction: column; align-items: center; gap: 0.1rem;
    padding: 0.6rem; background: var(--bg-glass); border: 1px solid var(--border-color); border-radius: var(--radius-lg);
}
.chip-val { font-size: 1.35rem; font-weight: 800; font-family: var(--font-mono); line-height: 1; }
.chip-key { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-muted); }
.chip-good .chip-val { color: var(--success); }
.chip-bad .chip-val { color: var(--danger); }

/* ---------- Flashcard (3D flip) ---------- */
.card-stage { perspective: 1600px; margin-bottom: 1.5rem; }
.flashcard {
    position: relative; width: 100%; min-height: 320px; cursor: pointer;
    border-radius: var(--radius-2xl);
}
.flashcard:focus-visible { outline: 2px solid var(--primary-400); outline-offset: 4px; }
.flashcard-inner {
    position: relative; width: 100%; min-height: 320px;
    transition: transform 0.6s var(--easing-bounce);
    transform-style: preserve-3d;
}
.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }

.flashcard-face {
    position: absolute; inset: 0; width: 100%; height: 100%;
    -webkit-backface-visibility: hidden; backface-visibility: hidden;
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    padding: 2.5rem 2rem; text-align: center;
    background: var(--bg-glass); backdrop-filter: var(--blur-md); -webkit-backdrop-filter: var(--blur-md);
    border: 1px solid var(--border-color); border-radius: var(--radius-2xl);
    overflow: auto;
}
.flashcard-front { box-shadow: 0 20px 50px -20px rgba(3,169,244,0.35); }
.flashcard-back { transform: rotateY(180deg); box-shadow: 0 20px 50px -20px rgba(0,212,255,0.4); border-color: rgba(0,212,255,0.25); }

.face-tag {
    position: absolute; top: 1.1rem; left: 1.1rem;
    font-family: var(--font-mono); font-size: 0.7rem; font-weight: 600;
    text-transform: uppercase; letter-spacing: 0.08em;
    padding: 0.28rem 0.7rem; border-radius: var(--radius-full);
    color: var(--primary-400); background: rgba(3,169,244,0.1); border: 1px solid rgba(3,169,244,0.25);
}
.tag-answer { color: var(--accent-cyan); background: rgba(0,212,255,0.1); border-color: rgba(0,212,255,0.3); }

.face-content { font-size: clamp(1.15rem, 3vw, 1.6rem); font-weight: 500; line-height: 1.5; max-width: 100%; }
.face-content.small { font-size: clamp(1rem, 2.4vw, 1.25rem); }
.flip-hint { position: absolute; bottom: 1.1rem; left: 0; right: 0; font-size: 0.78rem; color: var(--text-muted); }

kbd {
    font-family: var(--font-mono); font-size: 0.78em; padding: 0.1em 0.45em;
    background: var(--bg-glass-hover); border: 1px solid var(--border-hover);
    border-bottom-width: 2px; border-radius: 5px; color: var(--text-secondary);
}

/* Rendered markdown inside faces */
.face-content h1, .face-content h2, .face-content h3, .face-content h4 { line-height: 1.25; margin: 0.4em 0; }
.face-content h1 { font-size: 1.4em; } .face-content h2 { font-size: 1.25em; } .face-content h3 { font-size: 1.1em; }
.face-content p { margin: 0.5em 0; }
.face-content p:first-child { margin-top: 0; } .face-content p:last-child { margin-bottom: 0; }
.face-content ul, .face-content ol { text-align: left; margin: 0.5em auto; padding-left: 1.6em; max-width: max-content; }
.face-content li { margin: 0.25em 0; }
.face-content a { color: var(--primary-400); text-decoration: underline; }
.face-content strong { color: var(--text-primary); font-weight: 700; }
.face-content code {
    font-family: var(--font-mono); font-size: 0.88em; padding: 0.12em 0.4em;
    background: var(--bg-code); border: 1px solid var(--border-color); border-radius: 5px; color: var(--accent-cyan);
}
.face-content pre {
    text-align: left; background: var(--bg-code); border: 1px solid var(--border-color);
    border-radius: var(--radius-md); padding: 0.9rem 1rem; overflow-x: auto; margin: 0.6em 0;
    font-size: 0.82rem; line-height: 1.5;
}
.face-content pre code { background: none; border: none; padding: 0; color: var(--text-secondary); font-size: inherit; }
.face-content blockquote { border-left: 3px solid var(--primary-500); padding-left: 0.9em; margin: 0.5em 0; color: var(--text-muted); text-align: left; }
.face-content img { display: inline-block; margin: 0.4em auto; border-radius: var(--radius-md); }

/* ---------- Grade buttons ---------- */
.grade-row { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 0.75rem; margin-bottom: 1.25rem; }
.btn-grade { padding: 1rem 0.75rem; font-size: 0.95rem; }
.btn-grade kbd { margin-left: 0.15rem; }
.btn-flip { background: var(--bg-glass); color: var(--text-primary); border: 1px solid var(--border-color); }
.btn-flip:hover { background: var(--bg-glass-hover); border-color: var(--border-hover); transform: translateY(-2px); }
.btn-wrong { background: rgba(244, 63, 110, 0.12); color: var(--danger); border: 1px solid rgba(244, 63, 110, 0.35); }
.btn-wrong:hover { background: rgba(244, 63, 110, 0.2); transform: translateY(-2px); box-shadow: 0 8px 24px var(--danger-glow); }
.btn-right { background: rgba(34, 197, 94, 0.12); color: var(--success); border: 1px solid rgba(34, 197, 94, 0.35); }
.btn-right:hover { background: rgba(34, 197, 94, 0.2); transform: translateY(-2px); box-shadow: 0 8px 24px var(--success-glow); }
.btn-grade:disabled { opacity: 0.4; cursor: not-allowed; transform: none !important; box-shadow: none !important; }

.study-controls { text-align: center; color: var(--text-muted); font-size: 0.85rem; }
.dot-sep { margin: 0 0.6rem; opacity: 0.5; }

/* ---------- Complete view ---------- */
.view-complete { max-width: 640px; }
.complete-card { text-align: center; padding: 3rem 2rem; }
.complete-icon { color: var(--accent-cyan); margin-bottom: 1rem; filter: drop-shadow(var(--glow-accent)); animation: fadeUp 0.6s var(--easing-bounce) both; }
.complete-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin: 2rem 0; }
.cstat { padding: 1.2rem 0.75rem; background: var(--bg-glass); border: 1px solid var(--border-color); border-radius: var(--radius-lg); }
.cstat-val { display: block; font-size: 1.8rem; font-weight: 800; font-family: var(--font-mono); background: var(--gradient-secondary); background-clip: text; -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.cstat-key { font-size: 0.75rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.04em; }
.complete-actions { display: flex; gap: 0.85rem; justify-content: center; flex-wrap: wrap; }

/* ---------- Footer ---------- */
.footer { text-align: center; padding: 2rem 1.5rem; color: var(--text-muted); font-size: 0.85rem; border-top: 1px solid var(--border-color); }
.footer a { color: var(--primary-400); }
.footer a:hover { color: var(--accent-cyan); }

/* ---------- Card enter animation ---------- */
.flashcard.dealing { animation: dealIn 0.4s var(--easing-bounce) both; }
@keyframes dealIn { from { opacity: 0; transform: translateY(24px) scale(0.96); } to { opacity: 1; transform: translateY(0) scale(1); } }

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
    .upload-grid { grid-template-columns: 1fr; }
    .nav-link { display: none; }
}
@media (max-width: 560px) {
    .container { padding: 0 1rem; }
    .grade-row { gap: 0.5rem; }
    .btn-grade { padding: 0.85rem 0.5rem; font-size: 0.85rem; }
    .btn-grade span { display: flex; flex-direction: column; gap: 0.15rem; align-items: center; }
    .complete-stats { grid-template-columns: 1fr; }
    .glass-card { padding: 1.5rem; }
    .flashcard-face { padding: 2rem 1.25rem; }
}

@media (prefers-reduced-motion: reduce) {
    * { animation-duration: 0.01ms !important; transition-duration: 0.05ms !important; }
    .flashcard-inner { transition: transform 0.2s ease; }
    #bg-canvas { display: none; }
}