/* Quick Explainer — Editorial Design System */

:root {
    /* Colors — Warm Paper Aesthetic */
    --bg-primary: #FAF8F5;
    --bg-secondary: #F5F2ED;
    --bg-tertiary: #EFEAE3;
    --bg-input: #FFFFFF;
    --text-primary: #1A1A1A;
    --text-secondary: #5A5A5A;
    --text-muted: #8A8A8A;
    --accent: #C45C3E;
    --accent-hover: #B04D32;
    --accent-light: #E8D5CF;
    --border: #E0DCD5;
    --border-focus: #C45C3E;
    --shadow: rgba(26, 26, 26, 0.06);
    --shadow-hover: rgba(26, 26, 26, 0.12);
    
    /* Typography */
    --font-display: 'DM Serif Display', Georgia, serif;
    --font-body: 'Source Sans 3', -apple-system, sans-serif;
    
    /* Spacing */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;
    
    /* MiniSnackbar */
    --mini-snackbar-bg: var(--text-primary);
    --mini-snackbar-text: var(--bg-primary);
    --mini-snackbar-radius: var(--radius-md);
    --mini-snackbar-font-family: var(--font-body);
    --mini-snackbar-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

/* Dark Mode */
[data-theme="dark"] {
    --bg-primary: #1A1A1A;
    --bg-secondary: #2A2A2A;
    --bg-tertiary: #3A3A3A;
    --bg-input: #2A2A2A;
    --text-primary: #FAF8F5;
    --text-secondary: #C5C5C5;
    --text-muted: #8A8A8A;
    --accent: #E07B5A;
    --accent-hover: #F09274;
    --accent-light: #3A2A26;
    --border: #3A3A3A;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.5);
    
    /* MiniSnackbar Dark */
    --mini-snackbar-bg: #2A2A2A;
    --mini-snackbar-text: #FAF8F5;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Paper Grain Texture Overlay */
.grain-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    opacity: 0.02;
    z-index: -1;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 400 400' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
}

/* Container */
.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 60px 24px 40px;
    position: relative;
    z-index: 1;
    opacity: 1 !important;
    visibility: visible !important;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 48px;
    opacity: 1;
    visibility: visible;
}

main {
    opacity: 1;
    visibility: visible;
}

.logo {
    font-family: var(--font-display);
    font-size: 2.75rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.tagline {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 300;
    letter-spacing: 0.02em;
}

/* Settings Section */
.settings-section {
    margin-bottom: 32px;
}

.settings-toggle {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    font-family: var(--font-body);
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.settings-toggle:hover {
    background: var(--bg-tertiary);
    border-color: var(--border-focus);
}

.settings-icon {
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
}

.settings-text {
    flex: 1;
    text-align: left;
    margin-left: 12px;
}

.chevron {
    transition: transform var(--transition-normal);
    width: 16px;
    height: 16px;
    color: var(--text-muted);
}

.settings-toggle[aria-expanded="true"] .chevron {
    transform: rotate(180deg);
}

.settings-panel {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    padding: 24px 20px;
    margin-top: -8px;
    animation: slideDown var(--transition-normal) ease;
}

.settings-panel[hidden] {
    display: none;
}

.settings-grid {
    display: grid;
    gap: 20px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.input-group label {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.input-group input,
.input-group select {
    padding: 12px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.9375rem;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px var(--accent-light);
}

.input-group input::placeholder {
    color: var(--text-muted);
}

.input-group select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%235A5A5A' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
}

.refresh-models {
    position: absolute;
    right: 44px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    padding: 4px;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.refresh-models svg {
    width: 16px;
    height: 16px;
}

.refresh-models:hover {
    color: var(--accent);
    transform: translateY(-50%) rotate(180deg);
}

.input-group {
    position: relative;
}

.theme-toggle {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
}

.theme-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

.theme-btn svg {
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
}

.theme-btn:hover {
    background: var(--accent);
    border-color: var(--accent);
    transform: rotate(20deg);
}

.theme-btn:hover svg {
    color: white;
}

/* Input Section */
.input-section {
    margin-bottom: 40px;
}

.input-label {
    display: block;
    font-family: var(--font-display);
    font-size: 1.375rem;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.textarea-wrapper {
    position: relative;
}

textarea {
    width: 100%;
    padding: 20px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-primary);
    resize: vertical;
    min-height: 160px;
    transition: all var(--transition-normal);
}

textarea:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 4px 20px var(--shadow-hover);
}

textarea::placeholder {
    color: var(--text-muted);
}

.char-count {
    position: absolute;
    bottom: 12px;
    right: 16px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.controls-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 20px;
    gap: 16px;
    flex-wrap: wrap;
}

.explanation-level {
    display: flex;
    align-items: center;
    gap: 10px;
}

.explanation-level label {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.explanation-level select {
    padding: 10px 32px 10px 14px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.9375rem;
    color: var(--text-primary);
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%235A5A5A' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    transition: all var(--transition-fast);
}

.explanation-level select:focus {
    outline: none;
    border-color: var(--border-focus);
}

.explain-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: 0 4px 14px rgba(196, 92, 62, 0.3);
}

.explain-btn:hover:not(:disabled) {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(196, 92, 62, 0.4);
}

.explain-btn:disabled {
    background: var(--text-muted);
    cursor: not-allowed;
    box-shadow: none;
    opacity: 0.6;
}

.btn-loading {
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-loading[hidden] {
    display: none;
}

.spinner {
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* Output Section */
.output-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    margin-bottom: 32px;
    animation: fadeInUp var(--transition-slow) ease;
}

.output-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 16px;
}

.output-title {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--text-primary);
}

.output-actions {
    display: flex;
    gap: 10px;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.875rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.action-btn svg {
    width: 16px;
    height: 16px;
}

.action-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent);
    color: var(--accent);
}

.action-btn:hover svg {
    color: var(--accent);
}

.action-btn.copied {
    background: #D4F4D4;
    border-color: #4CAF50;
    color: #2E7D32;
}

.explanation-container {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 24px;
}

.explanation-text {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--text-primary);
}

/* Markdown Styles */
.explanation-text h1,
.explanation-text h2,
.explanation-text h3,
.explanation-text h4,
.explanation-text h5,
.explanation-text h6 {
    font-family: var(--font-display);
    margin-top: 1.5em;
    margin-bottom: 0.5em;
    color: var(--text-primary);
}

.explanation-text h1 { font-size: 1.75rem; }
.explanation-text h2 { font-size: 1.5rem; }
.explanation-text h3 { font-size: 1.25rem; }
.explanation-text h4 { font-size: 1.125rem; }
.explanation-text h5,
.explanation-text h6 { font-size: 1rem; }

.explanation-text p {
    margin-bottom: 1em;
}

.explanation-text p:last-child {
    margin-bottom: 0;
}

.explanation-text ul,
.explanation-text ol {
    margin: 1em 0;
    padding-left: 1.5em;
}

.explanation-text li {
    margin-bottom: 0.5em;
}

.explanation-text code {
    background: var(--bg-tertiary);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-family: 'Monaco', 'Menlo', 'Consolas', monospace;
    font-size: 0.9em;
    color: var(--text-primary);
}

.explanation-text pre {
    background: var(--bg-tertiary);
    padding: 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin: 1em 0;
}

.explanation-text pre code {
    background: none;
    padding: 0;
    font-size: 0.875rem;
}

.explanation-text blockquote {
    border-left: 4px solid var(--accent);
    padding-left: 1em;
    margin: 1em 0;
    color: var(--text-secondary);
    font-style: italic;
}

.explanation-text table {
    width: 100%;
    border-collapse: collapse;
    margin: 1em 0;
}

.explanation-text th,
.explanation-text td {
    border: 1px solid var(--border);
    padding: 8px 12px;
    text-align: left;
}

.explanation-text th {
    background: var(--bg-secondary);
    font-weight: 600;
}

.explanation-text hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 1.5em 0;
}

.explanation-text a {
    color: var(--accent);
    text-decoration: underline;
}

.explanation-text a:hover {
    color: var(--accent-hover);
}

.explanation-text strong {
    font-weight: 600;
}

.explanation-text em {
    font-style: italic;
}

.explanation-text p {
    margin-bottom: 16px;
}

.explanation-text p:last-child {
    margin-bottom: 0;
}

.output-meta {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
    font-size: 0.8125rem;
    color: var(--text-muted);
}

/* History Section */
.history-section {
    margin-top: 40px;
}

.history-title {
    font-family: var(--font-display);
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.history-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 16px 20px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.history-item:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent);
    transform: translateX(4px);
}

.history-input {
    font-size: 0.9375rem;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.history-meta {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    gap: 12px;
}

.clear-history {
    margin-top: 16px;
    padding: 8px 16px;
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 0.875rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.clear-history:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Footer */
footer {
    text-align: center;
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

footer p {
    font-size: 0.8125rem;
    color: var(--text-muted);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        max-height: 0;
    }
    to {
        opacity: 1;
        max-height: 500px;
    }
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.fade-in-up {
    animation: fadeInUp var(--transition-slow) ease forwards;
}

/* Typewriter cursor effect for output */
.explanation-text.typing::after {
    content: '|';
    animation: blink 1s step-end infinite;
    color: var(--accent);
}

@keyframes blink {
    50% {
        opacity: 0;
    }
}

/* Responsive Design */
@media (max-width: 600px) {
    .container {
        padding: 40px 16px 32px;
    }
    
    .logo {
        font-size: 2rem;
    }
    
    .tagline {
        font-size: 1rem;
    }
    
    .controls-row {
        flex-direction: column;
        align-items: stretch;
    }
    
    .explain-btn {
        width: 100%;
        justify-content: center;
    }
    
    .output-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .output-title {
        font-size: 1.25rem;
    }
}

/* Print Styles */
@media print {
    .settings-section,
    .input-section,
    .history-section,
    footer,
    .grain-overlay {
        display: none !important;
    }
    
    .output-section {
        border: none;
        background: white;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .fade-in-up {
        opacity: 1;
    }
}

/* Focus Visible */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Selection Color */
::selection {
    background: var(--accent-light);
    color: var(--text-primary);
}