/* =============================================
   CSS Design System — Trillex Dictionary
   ============================================= */

:root {
    /* Color palette */
    --color-bg: #0a0e1a;
    --color-surface: #111827;
    --color-surface-2: #1a2236;
    --color-surface-3: #222d44;
    --color-border: rgba(255, 255, 255, 0.06);
    --color-border-hover: rgba(255, 255, 255, 0.12);
    --color-text: #e8eaed;
    --color-text-secondary: #9ca3af;
    --color-text-muted: #6b7280;

    /* Language accent colors */
    --color-de: #f59e0b;
    --color-de-dim: rgba(245, 158, 11, 0.15);
    --color-en: #3b82f6;
    --color-en-dim: rgba(59, 130, 246, 0.15);
    --color-ru: #ef4444;
    --color-ru-dim: rgba(239, 68, 68, 0.15);

    /* Accent gradient */
    --gradient-accent: linear-gradient(135deg, var(--color-de), var(--color-en), var(--color-ru));
    --gradient-glow: linear-gradient(135deg, rgba(245,158,11,0.2), rgba(59,130,246,0.2), rgba(239,68,68,0.2));

    /* Category colors */
    --cat-noun: #a78bfa;
    --cat-verb: #34d399;
    --cat-adj: #fbbf24;
    --cat-phrase: #f472b6;
    --cat-other: #94a3b8;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.7rem;
    --font-size-sm: 0.8rem;
    --font-size-base: 0.9rem;
    --font-size-lg: 1.05rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.6rem;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    /* Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 40px rgba(59,130,246,0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
}

/* =============================================
   Reset & Base
   ============================================= */

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

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

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 400px;
    background: radial-gradient(ellipse at 50% 0%, rgba(59,130,246,0.08) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}

/* =============================================
   App Layout
   ============================================= */

.app {
    position: relative;
    z-index: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    max-width: 900px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

/* =============================================
   Header
   ============================================= */

.header {
    text-align: center;
    padding: var(--space-xl) 0 var(--space-lg);
}

.logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

.logo-icon {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--font-size-sm);
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-xs);
}

.logo-lang {
    cursor: pointer;
    transition: opacity var(--transition-fast);
    user-select: none;
}

.logo-lang:hover {
    opacity: 0.8;
}

.logo-lang[data-lang="de"] { color: var(--color-de); }
.logo-lang[data-lang="en"] { color: var(--color-en); }
.logo-lang[data-lang="ru"] { color: var(--color-ru); }
.logo-separator { color: var(--color-text-muted); }

.logo h1 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.tagline {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    font-weight: 400;
}

/* =============================================
   Search
   ============================================= */

.search-container {
    position: sticky;
    top: 0;
    z-index: 10;
    padding: var(--space-sm) 0 var(--space-md);
    background: linear-gradient(to bottom, var(--color-bg) 60%, transparent);
}

.search-box {
    display: flex;
    gap: var(--space-sm);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-xs);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-md);
}

.search-box:focus-within {
    border-color: rgba(59, 130, 246, 0.4);
    box-shadow: var(--shadow-md), 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-input-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 0 var(--space-md);
}

#source-lang {
    background: var(--color-surface-2);
    border: 1px solid var(--color-border);
    color: var(--color-text);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
    flex-shrink: 0;
}

#source-lang:hover {
    border-color: var(--color-border-hover);
}

#source-lang:focus {
    outline: none;
    border-color: var(--color-en);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.1);
}

.search-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.search-box:focus-within .search-icon {
    color: var(--color-en);
}

#search-input {
    flex: 1;
    background: none;
    border: none;
    outline: none;
    color: var(--color-text);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    padding: var(--space-sm) 0;
    min-width: 0;
}

#search-input::placeholder {
    color: var(--color-text-muted);
}

.clear-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    padding: 4px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.clear-btn:hover {
    color: var(--color-text);
    background: var(--color-surface-3);
}

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

.search-btn {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    background: var(--gradient-accent);
    border: none;
    color: white;
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    font-weight: 600;
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.search-btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.3);
}

.search-btn:active {
    transform: translateY(0);
}

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

/* =============================================
   Loading State
   ============================================= */

.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-2xl);
}

.spinner {
    width: 36px;
    height: 36px;
    border: 3px solid var(--color-surface-3);
    border-top-color: var(--color-en);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading p {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

/* =============================================
   Error State
   ============================================= */

.error {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: rgba(239, 68, 68, 0.08);
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: var(--radius-md);
    margin-top: var(--space-md);
}

.error svg {
    width: 24px;
    height: 24px;
    color: var(--color-ru);
    flex-shrink: 0;
}

.error p {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* =============================================
   Results
   ============================================= */

.results {
    flex: 1;
    padding-bottom: var(--space-xl);
}

.results-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--color-border);
}

.results-header h2 {
    font-size: var(--font-size-lg);
    font-weight: 600;
}

.results-count {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    background: var(--color-surface-2);
    padding: 2px 8px;
    border-radius: var(--radius-full);
}

/* Results table */
.results-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: var(--space-lg);
    table-layout: auto;
}

.results-table thead {
    border-bottom: 2px solid var(--color-border);
}

.results-table th {
    text-align: left;
    padding: var(--space-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: opacity var(--transition-fast);
    user-select: none;
}

.results-table th:hover {
    opacity: 0.8;
}

.results-table th.ru-column {
    color: var(--color-ru);
}

.results-table th.de-column {
    color: var(--color-de);
}

.results-table th.en-column {
    color: var(--color-en);
}

.translation-row {
    border-bottom: 1px solid var(--color-border);
    transition: background var(--transition-fast);
}

.translation-row:hover {
    background: var(--color-surface);
}

.translation-cell {
    padding: var(--space-md);
    font-size: var(--font-size-sm);
    vertical-align: top;
    line-height: 1.5;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.ru-cell {
    border-right: 1px solid var(--color-border);
}

.de-cell {
    border-right: 1px solid var(--color-border);
}

/* Desktop: Fixed column widths */
@media (min-width: 641px) {
    .results-table {
        table-layout: fixed;
    }

    .results-table th {
        width: 33.333%;
    }

    .translation-cell {
        width: 33.333%;
    }
}

/* Dictionary pair header */
.pair-section {
    animation: fadeInUp 0.4s ease both;
}

.pair-section:nth-child(2) { animation-delay: 0.1s; }
.pair-section:nth-child(3) { animation-delay: 0.2s; }

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.pair-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-md);
}

.pair-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: var(--font-size-xs);
    font-weight: 600;
    letter-spacing: 0.04em;
    padding: 3px 10px;
    border-radius: var(--radius-full);
    background: var(--color-surface-2);
    border: 1px solid var(--color-border);
}

.pair-badge .lang-left {
    color: var(--left-color);
}
.pair-badge .lang-right {
    color: var(--right-color);
}
.pair-badge .arrow {
    color: var(--color-text-muted);
    font-size: 10px;
}

.pair-section-count {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

/* Category group within a pair */
.category-group {
    margin-bottom: var(--space-lg);
}

.category-label {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--cat-color, var(--cat-other));
    margin-bottom: var(--space-sm);
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    background: color-mix(in srgb, var(--cat-color, var(--cat-other)) 10%, transparent);
}

.category-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--cat-color, var(--cat-other));
}

/* Entry rows */
.entry-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}

.entry-row {
    transition: background var(--transition-fast);
}

.entry-row:hover {
    background: var(--color-surface);
}

.entry-cell {
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-size-sm);
    vertical-align: top;
    border-bottom: 1px solid var(--color-border);
    line-height: 1.5;
}

.entry-cell:first-child {
    border-right: 1px solid var(--color-border);
    width: 50%;
}

.entry-cell .word-main {
    font-weight: 500;
    color: var(--color-text);
}

.entry-cell .word-article {
    color: var(--color-text-muted);
    font-weight: 400;
}

.entry-cell .word-extra {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    font-style: italic;
}

.entry-cell .word-domain {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    background: var(--color-surface-3);
    padding: 1px 5px;
    border-radius: var(--radius-sm);
    margin-left: 4px;
}

.entry-cell .word-grammar {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    font-style: italic;
}

/* Language indicator on the cell */
.lang-indicator {
    display: inline-block;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    margin-right: 6px;
    vertical-align: middle;
    opacity: 0.6;
}

.lang-indicator.de { background: var(--color-de); }
.lang-indicator.en { background: var(--color-en); }
.lang-indicator.ru { background: var(--color-ru); }

/* =============================================
   Empty State
   ============================================= */

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-2xl);
    text-align: center;
    flex: 1;
}

.empty-illustration {
    width: 100px;
    height: 100px;
    color: var(--color-text-muted);
    opacity: 0.5;
    margin-bottom: var(--space-md);
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
}

.empty-state p {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
}

.empty-hint {
    font-size: var(--font-size-sm) !important;
    color: var(--color-text-muted) !important;
}

/* =============================================
   Footer
   ============================================= */

.footer {
    text-align: center;
    padding: var(--space-lg) 0;
    border-top: 1px solid var(--color-border);
    margin-top: auto;
}

.footer p {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

.footer a {
    color: var(--color-en);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* =============================================
   Utilities
   ============================================= */

.hidden {
    display: none !important;
}

/* =============================================
   Responsive
   ============================================= */

@media (max-width: 640px) {
    html {
        font-size: 15px;
    }

    .app {
        padding: 0 var(--space-sm);
    }

    .header {
        padding: var(--space-lg) 0 var(--space-md);
    }

    .logo h1 {
        font-size: var(--font-size-xl);
    }

    .search-box {
        flex-direction: column;
        border-radius: var(--radius-md);
    }

    #source-lang {
        width: auto;
        flex-shrink: 0;
    }

    .search-btn {
        width: 100%;
        justify-content: center;
        padding: var(--space-sm) var(--space-md);
    }

    .results-header {
        flex-direction: column;
        gap: var(--space-xs);
    }

@media (min-width: 641px) {
    .search-input-wrapper {
        flex-direction: row;
    }

    .results-table thead {
        display: table-header-group;
    }

    .translation-row {
        display: table-row;
        background: transparent;
        border: none;
        border-radius: 0;
        padding: 0;
        margin-bottom: 0;
    }

    .translation-cell {
        display: table-cell;
        background: transparent;
        border: none;
        padding: var(--space-md);
        font-size: var(--font-size-sm);
    }

    .translation-cell::before {
        display: none;
    }

    .ru-cell {
        border-right: 1px solid var(--color-border);
    }

    .de-cell {
        border-right: 1px solid var(--color-border);
    }

    .translation-row {
        border-bottom: 1px solid var(--color-border);
    }

    .translation-row:hover {
        background: var(--color-surface);
    }
}

@media (max-width: 380px) {
    html {
        font-size: 14px;
    }

    .search-box {
        gap: var(--space-xs);
        padding: var(--space-xs);
    }

    .search-input-wrapper {
        gap: var(--space-xs);
        padding: 0 var(--space-sm);
    }

    #source-lang {
        padding: 4px 6px;
        font-size: 11px;
        min-width: 45px;
    }

    .search-btn {
        padding: var(--space-xs) var(--space-sm);
        font-size: 11px;
    }

    .search-btn svg {
        width: 14px;
        height: 14px;
    }

    .results-table {
        margin-top: var(--space-md);
    }

    .results-table th {
        padding: 6px 4px;
        font-size: 10px;
    }

    .translation-cell {
        padding: 6px 4px;
        font-size: 12px;
    }
}