/* ============================================================
   AI Prompt Generator — Design System
   ============================================================ */

:root {
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --space-xs: 4px; --space-sm: 8px; --space-md: 16px; --space-lg: 24px;
    --space-xl: 32px; --space-2xl: 48px; --space-3xl: 64px;
    --radius-sm: 8px; --radius-md: 12px; --radius-lg: 16px; --radius-xl: 20px; --radius-full: 9999px;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
    --duration: 200ms; --duration-slow: 400ms;
    --gradient: linear-gradient(135deg, #8B5CF6, #6366F1, #06B6D4);
    --gradient-text: linear-gradient(135deg, #A78BFA, #818CF8, #22D3EE);
    --gradient-btn: linear-gradient(135deg, #8B5CF6, #6366F1);
    --gradient-btn-hover: linear-gradient(135deg, #7C3AED, #4F46E5);
}

[data-theme="dark"] {
    --bg-body: #0B0F1A; --bg-card: rgba(17,24,45,0.7); --bg-card-solid: #111829;
    --bg-input: rgba(30,41,72,0.6); --bg-input-focus: rgba(40,54,94,0.8);
    --bg-hover: rgba(139,92,246,0.08); --bg-chip: rgba(139,92,246,0.1);
    --bg-chip-active: rgba(139,92,246,0.25); --bg-output: rgba(10,15,30,0.6);
    --bg-drawer: rgba(13,18,36,0.97);
    --border: rgba(148,163,184,0.1); --border-focus: rgba(139,92,246,0.5);
    --border-chip: rgba(139,92,246,0.2); --border-chip-active: rgba(139,92,246,0.5);
    --text-primary: #F1F5F9; --text-secondary: #94A3B8; --text-tertiary: #64748B; --text-accent: #A78BFA;
    --shadow-card: 0 8px 32px rgba(0,0,0,0.3), 0 0 0 1px rgba(148,163,184,0.06);
    --shadow-btn: 0 4px 20px rgba(139,92,246,0.3); --shadow-btn-hover: 0 8px 30px rgba(139,92,246,0.45);
    --blob-1: rgba(139,92,246,0.15); --blob-2: rgba(6,182,212,0.1); --blob-3: rgba(99,102,241,0.12);
    --scrollbar-thumb: rgba(148,163,184,0.2);
}

[data-theme="light"] {
    --bg-body: #F8FAFC; --bg-card: rgba(255,255,255,0.8); --bg-card-solid: #FFFFFF;
    --bg-input: rgba(241,245,249,0.8); --bg-input-focus: rgba(241,245,249,1);
    --bg-hover: rgba(139,92,246,0.05); --bg-chip: rgba(139,92,246,0.06);
    --bg-chip-active: rgba(139,92,246,0.14); --bg-output: rgba(248,250,252,0.8);
    --bg-drawer: rgba(255,255,255,0.97);
    --border: rgba(148,163,184,0.2); --border-focus: rgba(139,92,246,0.4);
    --border-chip: rgba(139,92,246,0.15); --border-chip-active: rgba(139,92,246,0.4);
    --text-primary: #0F172A; --text-secondary: #475569; --text-tertiary: #94A3B8; --text-accent: #7C3AED;
    --shadow-card: 0 8px 32px rgba(0,0,0,0.06), 0 0 0 1px rgba(148,163,184,0.1);
    --shadow-btn: 0 4px 20px rgba(139,92,246,0.2); --shadow-btn-hover: 0 8px 30px rgba(139,92,246,0.35);
    --blob-1: rgba(139,92,246,0.08); --blob-2: rgba(6,182,212,0.06); --blob-3: rgba(99,102,241,0.07);
    --scrollbar-thumb: rgba(148,163,184,0.35);
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
    font-family: var(--font); background: var(--bg-body); color: var(--text-primary);
    min-height: 100vh; line-height: 1.6; overflow-x: hidden;
    transition: background var(--duration-slow) var(--ease), color var(--duration-slow) var(--ease);
}
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: var(--radius-full); }

/* Background blobs */
.bg-blobs { position: fixed; inset: 0; z-index: 0; overflow: hidden; pointer-events: none; }
.blob { position: absolute; border-radius: 50%; filter: blur(100px); animation: blobFloat 20s ease-in-out infinite; }
.blob-1 { width: 500px; height: 500px; background: var(--blob-1); top: -10%; right: -5%; }
.blob-2 { width: 400px; height: 400px; background: var(--blob-2); bottom: 5%; left: -8%; animation-delay: -7s; }
.blob-3 { width: 350px; height: 350px; background: var(--blob-3); top: 40%; left: 50%; animation-delay: -14s; }
@keyframes blobFloat {
    0%, 100% { transform: translate(0,0) scale(1); }
    25% { transform: translate(30px,-40px) scale(1.05); }
    50% { transform: translate(-20px,20px) scale(0.95); }
    75% { transform: translate(40px,30px) scale(1.02); }
}

/* Header */
.header {
    position: sticky; top: 0; z-index: 100;
    background: var(--bg-card); backdrop-filter: blur(20px) saturate(180%); -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border); transition: background var(--duration-slow) var(--ease);
}
.header-inner { max-width: 1200px; margin: 0 auto; padding: var(--space-md) var(--space-lg); display: flex; align-items: center; justify-content: space-between; }
.logo { display: flex; align-items: center; gap: var(--space-sm); }
.logo-icon { display: flex; transition: transform var(--duration) var(--ease); }
.logo:hover .logo-icon { transform: rotate(-5deg) scale(1.05); }
.logo-text { font-size: 1.25rem; font-weight: 700; letter-spacing: -0.02em; background: var(--gradient-text); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.header-actions { display: flex; align-items: center; gap: var(--space-sm); }
.icon-btn {
    position: relative; display: flex; align-items: center; justify-content: center; width: 40px; height: 40px;
    border-radius: var(--radius-sm); border: 1px solid var(--border); background: var(--bg-input);
    color: var(--text-secondary); cursor: pointer; transition: all var(--duration) var(--ease);
}
.icon-btn:hover { background: var(--bg-hover); color: var(--text-accent); border-color: var(--border-focus); }
.history-badge {
    position: absolute; top: -4px; right: -4px; min-width: 18px; height: 18px; padding: 0 5px;
    border-radius: var(--radius-full); background: var(--gradient-btn); color: #fff;
    font-size: 0.65rem; font-weight: 700; display: flex; align-items: center; justify-content: center;
}
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }
[data-theme="light"] .icon-sun { display: none; }
[data-theme="light"] .icon-moon { display: block; }

/* Main & Hero */
.main { position: relative; z-index: 1; max-width: 1200px; margin: 0 auto; padding: var(--space-xl) var(--space-lg) var(--space-3xl); }
.hero { text-align: center; padding: var(--space-2xl) 0 var(--space-xl); }
.hero-title { font-size: clamp(2rem,5vw,3.25rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.15; margin-bottom: var(--space-md); }
.gradient-text { background: var(--gradient-text); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-subtitle { font-size: clamp(1rem,2vw,1.15rem); color: var(--text-secondary); max-width: 600px; margin: 0 auto; font-weight: 400; line-height: 1.7; }

/* Generator Card */
.generator-card {
    background: var(--bg-card); backdrop-filter: blur(24px) saturate(180%); -webkit-backdrop-filter: blur(24px) saturate(180%);
    border: 1px solid var(--border); border-radius: var(--radius-xl); box-shadow: var(--shadow-card); overflow: hidden;
    transition: background var(--duration-slow) var(--ease), border-color var(--duration-slow) var(--ease);
}
.card-inner { display: grid; grid-template-columns: 1fr 1fr; min-height: 520px; }
.input-section, .output-section { padding: var(--space-xl); }
.input-section { border-right: 1px solid var(--border); }
.section-label { font-size: 0.8rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-accent); margin-bottom: var(--space-lg); }

/* Form Fields */
.field { margin-bottom: var(--space-lg); }
.field-label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--text-primary); margin-bottom: var(--space-sm); }
.optional-tag { font-weight: 400; font-size: 0.75rem; color: var(--text-tertiary); margin-left: var(--space-xs); }
.select-wrapper { position: relative; }
.select-wrapper select {
    width: 100%; appearance: none; -webkit-appearance: none; padding: 12px 40px 12px 14px;
    font-family: var(--font); font-size: 0.9rem; color: var(--text-primary); background: var(--bg-input);
    border: 1px solid var(--border); border-radius: var(--radius-md); cursor: pointer; transition: all var(--duration) var(--ease);
}
.select-wrapper select:focus { outline: none; background: var(--bg-input-focus); border-color: var(--border-focus); box-shadow: 0 0 0 3px rgba(139,92,246,0.1); }
.select-chevron { position: absolute; right: 14px; top: 50%; transform: translateY(-50%); color: var(--text-tertiary); pointer-events: none; }
textarea, input[type="text"] {
    width: 100%; padding: 12px 14px; font-family: var(--font); font-size: 0.9rem; color: var(--text-primary);
    background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-md); resize: vertical; transition: all var(--duration) var(--ease);
}
textarea:focus, input[type="text"]:focus { outline: none; background: var(--bg-input-focus); border-color: var(--border-focus); box-shadow: 0 0 0 3px rgba(139,92,246,0.1); }
textarea::placeholder, input::placeholder { color: var(--text-tertiary); }

/* Tone Chips */
.tone-group { display: flex; flex-wrap: wrap; gap: var(--space-sm); }
.tone-chip { cursor: pointer; }
.tone-chip input { position: absolute; opacity: 0; pointer-events: none; }
.tone-chip span {
    display: inline-block; padding: 8px 16px; font-size: 0.82rem; font-weight: 500;
    border-radius: var(--radius-full); border: 1px solid var(--border-chip); background: var(--bg-chip);
    color: var(--text-secondary); transition: all var(--duration) var(--ease); user-select: none;
}
.tone-chip input:checked + span { background: var(--bg-chip-active); border-color: var(--border-chip-active); color: var(--text-accent); box-shadow: 0 0 12px rgba(139,92,246,0.15); }
.tone-chip:hover span { border-color: var(--border-chip-active); }

/* Generate Button */
.generate-btn {
    display: flex; align-items: center; justify-content: center; gap: var(--space-sm); width: 100%; padding: 14px;
    font-family: var(--font); font-size: 0.95rem; font-weight: 600; color: #fff; background: var(--gradient-btn);
    border: none; border-radius: var(--radius-md); cursor: pointer; box-shadow: var(--shadow-btn);
    transition: all var(--duration) var(--ease); margin-top: var(--space-sm);
}
.generate-btn:hover:not(:disabled) { background: var(--gradient-btn-hover); box-shadow: var(--shadow-btn-hover); transform: translateY(-1px); }
.generate-btn:active:not(:disabled) { transform: translateY(0); }
.generate-btn:disabled { opacity: 0.45; cursor: not-allowed; box-shadow: none; }
.generate-btn.loading span { display: none; }
.generate-btn.loading svg { display: none; }
.generate-btn.loading::after {
    content: ''; width: 20px; height: 20px; border: 2px solid rgba(255,255,255,0.3);
    border-top-color: #fff; border-radius: 50%; animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Output Section */
.output-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--space-md); flex-wrap: wrap; gap: var(--space-sm); }
.output-actions { display: flex; align-items: center; gap: var(--space-md); }
.char-count { font-size: 0.75rem; color: var(--text-tertiary); font-variant-numeric: tabular-nums; }
.copy-btn {
    display: flex; align-items: center; gap: 6px; padding: 7px 14px; font-family: var(--font);
    font-size: 0.8rem; font-weight: 500; color: var(--text-accent); background: var(--bg-chip);
    border: 1px solid var(--border-chip); border-radius: var(--radius-full); cursor: pointer; transition: all var(--duration) var(--ease);
}
.copy-btn:hover { background: var(--bg-chip-active); border-color: var(--border-chip-active); }
.copy-btn .check-icon { display: none; }
.copy-btn.copied .copy-icon { display: none; }
.copy-btn.copied .check-icon { display: block; }
.copy-btn.copied .copy-label { color: #22C55E; }
.copy-btn.copied { border-color: rgba(34,197,94,0.3); background: rgba(34,197,94,0.08); }

.output-box {
    background: var(--bg-output); border: 1px solid var(--border); border-radius: var(--radius-md);
    min-height: 380px; display: flex; align-items: center; justify-content: center; position: relative;
    transition: all var(--duration-slow) var(--ease);
}
.empty-state { text-align: center; padding: var(--space-xl); color: var(--text-tertiary); }
.empty-icon { margin-bottom: var(--space-md); opacity: 0.4; }
.empty-state p { font-size: 0.95rem; font-weight: 500; color: var(--text-secondary); margin-bottom: var(--space-xs); }
.empty-state span { font-size: 0.82rem; }
.prompt-output {
    width: 100%; height: 100%; min-height: 380px; padding: var(--space-lg); font-family: var(--font);
    font-size: 0.88rem; line-height: 1.75; color: var(--text-primary); white-space: pre-wrap;
    word-wrap: break-word; overflow-y: auto; animation: fadeIn var(--duration-slow) var(--ease);
}
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

/* Examples Section */
.examples-section { margin-top: var(--space-3xl); }
.section-title { display: flex; align-items: center; gap: var(--space-sm); font-size: 1.25rem; font-weight: 700; margin-bottom: var(--space-sm); }
.section-title svg { color: var(--text-accent); }
.section-desc { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: var(--space-lg); }
.examples-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: var(--space-md); }
.example-card {
    background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border); border-radius: var(--radius-lg); padding: var(--space-lg);
    cursor: pointer; transition: all var(--duration) var(--ease); position: relative; overflow: hidden;
}
.example-card::before { content: ''; position: absolute; inset: 0; background: var(--gradient); opacity: 0; transition: opacity var(--duration) var(--ease); border-radius: inherit; }
.example-card:hover { border-color: var(--border-focus); transform: translateY(-2px); box-shadow: var(--shadow-card); }
.example-card:hover::before { opacity: 0.04; }
.example-card > * { position: relative; z-index: 1; }
.example-emoji { font-size: 1.5rem; margin-bottom: var(--space-sm); }
.example-title { font-size: 0.95rem; font-weight: 600; margin-bottom: var(--space-xs); }
.example-desc { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.5; }
.example-tags { display: flex; gap: 6px; margin-top: var(--space-sm); flex-wrap: wrap; }
.example-tag { font-size: 0.7rem; font-weight: 500; padding: 3px 10px; border-radius: var(--radius-full); background: var(--bg-chip); color: var(--text-accent); border: 1px solid var(--border-chip); }

/* History Drawer */
.history-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 200; opacity: 0; pointer-events: none; transition: opacity var(--duration-slow) var(--ease); }
.history-overlay.open { opacity: 1; pointer-events: auto; }
.history-drawer {
    position: fixed; top: 0; right: 0; width: min(420px, 90vw); height: 100vh;
    background: var(--bg-drawer); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
    border-left: 1px solid var(--border); z-index: 201; display: flex; flex-direction: column;
    transform: translateX(100%); transition: transform var(--duration-slow) var(--ease);
}
.history-drawer.open { transform: translateX(0); }
.drawer-header { display: flex; align-items: center; justify-content: space-between; padding: var(--space-lg); border-bottom: 1px solid var(--border); }
.drawer-header h2 { font-size: 1.05rem; font-weight: 700; }
.drawer-actions { display: flex; align-items: center; gap: var(--space-sm); }
.text-btn { font-family: var(--font); font-size: 0.8rem; font-weight: 500; padding: 6px 12px; border-radius: var(--radius-sm); border: none; background: transparent; cursor: pointer; transition: all var(--duration) var(--ease); }
.text-btn.danger { color: #EF4444; }
.text-btn.danger:hover { background: rgba(239,68,68,0.1); }
.drawer-body { flex: 1; overflow-y: auto; padding: var(--space-md); }
.empty-history { text-align: center; padding: var(--space-3xl) var(--space-lg); color: var(--text-tertiary); }
.empty-history svg { opacity: 0.3; margin-bottom: var(--space-md); }
.empty-history p { font-weight: 500; color: var(--text-secondary); margin-bottom: var(--space-xs); }
.empty-history span { font-size: 0.82rem; }
.history-item {
    background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-md);
    padding: var(--space-md); margin-bottom: var(--space-sm); cursor: pointer;
    transition: all var(--duration) var(--ease); animation: fadeIn var(--duration-slow) var(--ease);
}
.history-item:hover { border-color: var(--border-focus); background: var(--bg-hover); }
.history-meta { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--space-sm); }
.history-category { font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-accent); }
.history-time { font-size: 0.7rem; color: var(--text-tertiary); }
.history-preview { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.5; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.history-item-actions { display: flex; gap: var(--space-sm); margin-top: var(--space-sm); }
.history-copy-btn, .history-delete-btn {
    font-family: var(--font); font-size: 0.72rem; font-weight: 500; padding: 4px 10px;
    border-radius: var(--radius-sm); border: 1px solid var(--border); background: transparent;
    color: var(--text-secondary); cursor: pointer; transition: all var(--duration) var(--ease);
}
.history-copy-btn:hover { border-color: var(--border-focus); color: var(--text-accent); }
.history-delete-btn:hover { border-color: rgba(239,68,68,0.3); color: #EF4444; }

/* Footer */
.footer { position: relative; z-index: 1; text-align: center; padding: var(--space-xl) var(--space-lg); font-size: 0.82rem; color: var(--text-tertiary); border-top: 1px solid var(--border); }
.footer strong { background: var(--gradient-text); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

/* Responsive */
@media (max-width: 860px) {
    .card-inner { grid-template-columns: 1fr; }
    .input-section { border-right: none; border-bottom: 1px solid var(--border); }
    .output-box, .prompt-output { min-height: 280px; }
}
@media (max-width: 640px) {
    .hero { padding: var(--space-lg) 0; }
    .main { padding: var(--space-md) var(--space-md) var(--space-2xl); }
    .input-section, .output-section { padding: var(--space-lg); }
    .examples-grid { grid-template-columns: 1fr; }
}