/* ==========================================================================
   Binary Relation Analyzer - Clean Modern Minimal Design System
   Supports both Dark Mode and Light Mode
   ========================================================================== */

/* Dark Theme Variables (Default) */
:root, [data-theme="dark"] {
    --bg-dark: #090d16;
    --bg-card: #131a2a;
    --bg-card-hover: #192338;
    --bg-input: #0b111e;
    
    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-focus: #6366f1;
    
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --text-dim: #64748b;
    
    --accent-indigo: #6366f1;
    --accent-purple: #8b5cf6;
    --accent-glow: rgba(99, 102, 241, 0.25);
    
    --color-yes: #10b981;
    --color-yes-bg: rgba(16, 185, 129, 0.12);
    --color-yes-border: rgba(16, 185, 129, 0.3);
    
    --color-no: #f43f5e;
    --color-no-bg: rgba(244, 63, 94, 0.12);
    --color-no-border: rgba(244, 63, 94, 0.3);
    
    --color-gold: #f59e0b;
    --color-gold-bg: rgba(245, 158, 11, 0.12);
    --color-gold-border: rgba(245, 158, 11, 0.3);
    
    --preview-bg: #090e1a;
    --matrix-corner-bg: #0b111e;
    --matrix-header-bg: #0f172a;
    --matrix-zero-bg: #0b111e;
    --matrix-zero-text: #64748b;
    --matrix-one-bg: rgba(99, 102, 241, 0.18);
    --matrix-one-text: #ffffff;
    
    --node-fill: #1e293b;
    --node-text: #f8fafc;
    --node-stroke: #6366f1;
    
    --glow-opacity: 0.12;
}

/* Light Theme Variables */
[data-theme="light"] {
    --bg-dark: #f8fafc;
    --bg-card: #ffffff;
    --bg-card-hover: #f1f5f9;
    --bg-input: #ffffff;
    
    --border-subtle: #e2e8f0;
    --border-focus: #4f46e5;
    
    --text-main: #0f172a;
    --text-muted: #475569;
    --text-dim: #64748b;
    
    --accent-indigo: #4f46e5;
    --accent-purple: #7c3aed;
    --accent-glow: rgba(79, 70, 229, 0.15);
    
    --color-yes: #059669;
    --color-yes-bg: #ecfdf5;
    --color-yes-border: #a7f3d0;
    
    --color-no: #e11d48;
    --color-no-bg: #fff1f2;
    --color-no-border: #fecdd3;
    
    --color-gold: #d97706;
    --color-gold-bg: #fffbeb;
    --color-gold-border: #fde68a;
    
    --preview-bg: #f1f5f9;
    --matrix-corner-bg: #cbd5e1;
    --matrix-header-bg: #e2e8f0;
    --matrix-zero-bg: #ffffff;
    --matrix-zero-text: #94a3b8;
    --matrix-one-bg: #e0e7ff;
    --matrix-one-text: #3730a3;
    
    --node-fill: #ffffff;
    --node-text: #0f172a;
    --node-stroke: #4f46e5;
    
    --glow-opacity: 0.05;
}

/* Shared Design Tokens */
:root {
    --radius-lg: 16px;
    --radius-md: 10px;
    --radius-sm: 6px;
    
    --font-sans: 'Inter', -apple-system, system-ui, sans-serif;
    --font-mono: 'Fira Code', 'Courier New', monospace;
}

/* Global Reset & Core Body */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-sans);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 2.5rem 1rem;
    line-height: 1.5;
    position: relative;
    overflow-x: hidden;
    transition: background-color 0.25s ease, color 0.25s ease;
}

/* Ambient Radial Glow */
.background-glow {
    position: fixed;
    top: -150px;
    left: 50%;
    transform: translateX(-50%);
    width: 900px;
    height: 500px;
    background: radial-gradient(circle, rgba(99, 102, 241, var(--glow-opacity)) 0%, rgba(139, 92, 246, 0.04) 55%, transparent 75%);
    pointer-events: none;
    z-index: 0;
}

/* Container */
.app-container {
    width: 100%;
    max-width: 960px;
    z-index: 1;
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

/* Top Navigation / Theme Bar */
.top-bar {
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

.theme-toggle-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.45rem 0.9rem;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 9999px;
    color: var(--text-main);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
    border-color: var(--border-focus);
    transform: translateY(-1px);
}

/* Header */
.app-header {
    text-align: center;
}

.header-badge {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    background: var(--color-yes-bg);
    border: 1px solid var(--color-yes-border);
    border-radius: 9999px;
    color: var(--accent-indigo);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.app-header h1 {
    font-size: 2.1rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.02em;
    margin-bottom: 0.4rem;
}

.app-header p {
    color: var(--text-muted);
    font-size: 0.95rem;
    max-width: 640px;
    margin: 0 auto;
}

/* Base Card Style */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 1.75rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: background-color 0.25s ease, border-color 0.25s ease;
}

/* Centered Input Card */
.input-card {
    max-width: 720px;
    margin: 0 auto;
    width: 100%;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: flex;
    flex-direction: column;
    margin-bottom: 0.4rem;
}

.label-title {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-main);
}

.label-sub {
    font-size: 0.8rem;
    color: var(--text-dim);
}

input[type="text"] {
    width: 100%;
    padding: 0.8rem 1rem;
    background: var(--bg-input);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    color: var(--text-main);
    font-family: var(--font-mono);
    font-size: 0.95rem;
    outline: none;
    transition: all 0.2s ease;
}

input[type="text"]:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

/* Live Preview Box */
.live-preview-box {
    background: var(--preview-bg);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    margin-bottom: 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    transition: background-color 0.25s ease;
}

.preview-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-dim);
    text-transform: uppercase;
}

.preview-code {
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: var(--accent-purple);
    font-weight: 600;
}

.live-warning {
    font-size: 0.8rem;
    color: var(--color-gold);
    font-family: var(--font-sans);
}

/* Error Message Under Input Box */
.inline-error {
    background: var(--color-no-bg);
    border: 1px solid var(--color-no-border);
    color: var(--color-no);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.25rem;
}

/* Preset Buttons */
.preset-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.preset-title {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-dim);
    text-transform: uppercase;
}

.preset-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.btn-preset {
    padding: 0.35rem 0.75rem;
    background: var(--bg-card-hover);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-preset:hover {
    background: var(--accent-glow);
    border-color: var(--accent-indigo);
    color: var(--accent-indigo);
}

/* Check Button */
.btn-submit {
    width: 100%;
    padding: 0.9rem 1.5rem;
    background: linear-gradient(135deg, var(--accent-indigo) 0%, var(--accent-purple) 100%);
    border: none;
    border-radius: var(--radius-md);
    color: #ffffff;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    box-shadow: 0 4px 15px var(--accent-glow);
    transition: all 0.2s ease;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--accent-glow);
}

/* Parsed Strip */
.parsed-strip {
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    font-size: 0.9rem;
}

.parsed-strip-label {
    font-weight: 600;
    color: var(--text-dim);
}

.parsed-strip code {
    font-family: var(--font-mono);
    font-size: 0.95rem;
    background: var(--preview-bg);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    color: var(--text-main);
}

.parsed-strip code.highlight-code {
    color: var(--accent-purple);
    font-weight: 600;
}

/* Results Container & Spacing Structure */
.results-container {
    display: flex;
    flex-direction: column;
    gap: 32px; /* Clear 32px vertical gap between result sections */
}

.results-section {
    display: flex;
    flex-direction: column;
}

.section-title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 16px; /* 16px of space below each section heading */
    color: var(--text-main);
}

/* Grids with Consistent 24px Gap */
.classification-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px; /* Consistent 24px gap horizontally and vertically */
}

.properties-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px; /* Consistent 24px gap horizontally and vertically */
}

.visuals-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px; /* Consistent 24px gap horizontally and vertically */
}

/* Classification Cards */
.classification-card {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.classification-card.is-positive {
    border-color: var(--color-yes-border);
    background: var(--color-yes-bg);
}

.classification-card.is-negative {
    border-color: var(--border-subtle);
}

.classification-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.classification-header h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-main);
}

.req-checklist {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin: 0.2rem 0;
}

.req-item {
    font-size: 0.78rem;
    font-weight: 600;
    padding: 0.2rem 0.55rem;
    border-radius: 4px;
}

.req-item.req-ok {
    background: var(--color-yes-bg);
    color: var(--color-yes);
    border: 1px solid var(--color-yes-border);
}

.req-item.req-fail {
    background: var(--color-no-bg);
    color: var(--color-no);
    border: 1px solid var(--color-no-border);
}

.classification-reason {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.4;
    margin-top: 0.2rem;
}

/* Badges */
.badge {
    padding: 0.25rem 0.65rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.badge-yes {
    background: var(--color-yes-bg);
    color: var(--color-yes);
    border: 1px solid var(--color-yes-border);
}

.badge-no {
    background: var(--color-no-bg);
    color: var(--color-no);
    border: 1px solid var(--color-no-border);
}

/* Property Cards */
.prop-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.prop-card.is-yes {
    border-left: 5px solid var(--color-yes);
}

.prop-card.is-no {
    border-left: 5px solid var(--color-no);
}

.prop-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.prop-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.prop-card-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-main);
}

.prop-card-def code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--accent-purple);
    background: var(--preview-bg);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
}

.prop-card-reason {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.4;
}

/* Visuals Cards (Matrix & SVG Graph) */
.visual-card {
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-main);
}

.card-subtitle {
    font-size: 0.8rem;
    color: var(--text-dim);
    margin-bottom: 1rem;
}

/* Relation Matrix Table */
.matrix-wrapper {
    overflow-x: auto;
    display: flex;
    justify-content: center;
    padding: 0.5rem 0;
}

.relation-matrix {
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 0.95rem;
}

.relation-matrix th, .relation-matrix td {
    width: 42px;
    height: 42px;
    text-align: center;
    vertical-align: middle;
    border: 1px solid var(--border-subtle);
}

.matrix-corner {
    font-size: 0.75rem;
    color: var(--text-dim);
    background: var(--matrix-corner-bg);
}

.relation-matrix th {
    background: var(--matrix-header-bg);
    color: var(--text-muted);
    font-weight: 600;
}

.relation-matrix td.val-one {
    background: var(--matrix-one-bg);
    color: var(--matrix-one-text);
    font-weight: bold;
}

.relation-matrix td.val-zero {
    color: var(--matrix-zero-text);
    background: var(--matrix-zero-bg);
}

.relation-matrix td.val-diag {
    border: 2px solid var(--accent-purple);
}

/* SVG Graph */
.graph-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 320px;
}

.graph-svg {
    width: 100%;
    max-width: 360px;
    height: auto;
}

.node-circle {
    fill: var(--node-fill);
    stroke: var(--node-stroke);
    transition: fill 0.25s ease, stroke 0.25s ease;
}

.node-text {
    fill: var(--node-text);
    transition: fill 0.25s ease;
}

.empty-graph {
    color: var(--text-dim);
    font-size: 0.9rem;
    text-align: center;
}

/* Footer */
.app-footer {
    text-align: center;
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--text-dim);
}

/* Responsive Layout */
@media (max-width: 768px) {
    .classification-grid, .visuals-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .properties-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .results-container {
        gap: 32px;
    }
}