/* ================================================================
   Sankey Flow Studio — Design System
   Shared tokens, reset, and component styles for all pages.
   ================================================================ */

/* ---- Design Tokens ---- */
:root {
    --paper: #ede8e0;
    --ink: #2c2a27;
    --ink-light: #7a7a72;
    --ink-faint: #b0b0b0;
    --accent: #6b7c5e;
    --accent-hover: #576a4c;
    --accent-soft: #e4e0d6;
    --rule: #d5d0c8;
    --rule-light: #e4e0d6;
    --surface: #ffffff;
    --surface-muted: #f5f3f0;
    --danger: #c44;
    --danger-bg: #fef2f2;
    --danger-border: #fecaca;
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.08);
    --font-serif: 'Newsreader', Georgia, serif;
    --font-sans: 'DM Sans', sans-serif;
    --font-mono: 'IBM Plex Mono', monospace;
    --radius: 4px;
    --radius-sm: 3px;
}

/* ---- Reset ---- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
    font-family: var(--font-sans);
    background: var(--paper);
    color: var(--ink);
    min-height: 100vh;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* ---- Typography ---- */
h1, h2, h3 { font-family: var(--font-serif); font-weight: 400; line-height: 1.2; }
h1 { font-size: 2rem; letter-spacing: -0.01em; }
h2 { font-size: 1.35rem; }
h3 { font-size: 1.1rem; }

/* ---- Links ---- */
a { color: var(--accent); text-decoration: none; transition: color 0.12s; }
a:hover { text-decoration: underline; }

/* ---- Focus States ---- */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    font-family: var(--font-sans);
    font-size: 0.82rem;
    font-weight: 600;
    padding: 0.55rem 1.3rem;
    border: 1.5px solid transparent;
    border-radius: var(--radius);
    cursor: pointer;
    text-decoration: none;
    transition: background 0.15s, border-color 0.15s, color 0.15s, box-shadow 0.15s, opacity 0.15s;
    line-height: 1.3;
    white-space: nowrap;
}
.btn:hover { text-decoration: none; }
.btn:disabled { opacity: 0.4; cursor: not-allowed; pointer-events: none; }

.btn-accent { background: var(--accent); color: #fff !important; border-color: var(--accent); }
.btn-accent:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

.btn-ink { background: var(--ink); color: #fff; border-color: var(--ink); }
.btn-ink:hover { background: var(--accent); border-color: var(--accent); }

.btn-outline { background: transparent; color: var(--ink); border-color: var(--rule); }
.btn-outline:hover { border-color: var(--ink); }

.btn-danger { background: transparent; color: var(--danger); border-color: var(--danger); }
.btn-danger:hover { background: var(--danger); color: #fff; }

.btn-ghost { background: transparent; color: var(--ink-light); border-color: transparent; padding: 0.4rem 0.75rem; }
.btn-ghost:hover { color: var(--ink); background: var(--surface-muted); }

.btn-sm { font-size: 0.75rem; padding: 0.4rem 0.9rem; }
.btn-lg { font-size: 0.9rem; padding: 0.7rem 1.75rem; }

/* ---- Inputs ---- */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="url"],
input[type="number"],
textarea,
select {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    padding: 0.6rem 0.85rem;
    border: 1.5px solid var(--rule);
    border-radius: var(--radius);
    background: var(--surface);
    color: var(--ink);
    transition: border-color 0.15s, box-shadow 0.15s;
    width: 100%;
}
input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(107,124,94,0.12);
}
input::placeholder,
textarea::placeholder {
    color: var(--ink-faint);
}

/* ---- Labels ---- */
.label, .field label {
    display: block;
    font-family: var(--font-sans);
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--ink-light);
    margin-bottom: 0.4rem;
}
.label-hint { font-weight: 400; color: var(--ink-faint); text-transform: none; letter-spacing: 0; }

/* ---- Cards ---- */
.card, .section {
    background: var(--surface);
    border: 1.5px solid var(--rule);
    border-radius: var(--radius);
    padding: 1.5rem;
}
.section + .section { margin-top: 1rem; }
.section h2 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--rule-light);
}

/* ---- Flash / Alerts ---- */
.flash-msg {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    padding: 0.65rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    line-height: 1.5;
    color: #b91c1c;
    background: var(--danger-bg);
    border: 1px solid var(--danger-border);
}
.flash-msg.info {
    color: var(--ink);
    background: var(--surface-muted);
    border-color: var(--rule);
}
.flash-msg.success {
    color: #065f46;
    background: #ecfdf5;
    border-color: #a7f3d0;
}
.flash {
    background: var(--rule-light);
    padding: 0.65rem 1rem;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    border-radius: var(--radius);
    line-height: 1.5;
    white-space: pre-line;
}

/* ---- Tags / Badges ---- */
.tag-pill {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent);
    background: var(--accent-soft);
    padding: 0.2rem 0.55rem;
    border-radius: var(--radius-sm);
    text-decoration: none !important;
    transition: background 0.12s, color 0.12s;
}
.tag-pill:hover { background: var(--accent); color: #fff; }
.tag-pill.active { background: var(--accent); color: #fff; }

.badge {
    display: inline-block;
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding: 0.2rem 0.55rem;
    border-radius: var(--radius-sm);
}
.badge-pro, .badge-studio { background: var(--accent); color: #fff; }
.badge-free { background: var(--rule); color: var(--ink-light); }
.e2e-badge { font-size: 0.7rem; background: var(--accent); color: #fff; padding: 0.15rem 0.4rem; border-radius: var(--radius-sm); vertical-align: middle; }

/* ---- Site Navigation ---- */
.site-nav {
    border-bottom: 3px double var(--ink);
    padding: 1.1rem 0;
    background: var(--paper);
    position: sticky;
    top: 0;
    z-index: 100;
}
.site-nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.site-nav .logo {
    font-family: var(--font-serif);
    font-size: 1.35rem;
    color: var(--ink);
    text-decoration: none;
}
.site-nav .logo:hover { text-decoration: none; color: var(--accent); }
.nav-links { display: flex; gap: 1.5rem; align-items: center; }
.nav-links a {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--ink-light);
    text-decoration: none;
    transition: color 0.12s;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-links a.active { color: var(--ink); font-weight: 600; }

/* ---- Hamburger ---- */
.hamburger { display: none; background: none; border: none; cursor: pointer; padding: 0.5rem; }
.hamburger span { display: block; width: 22px; height: 2px; background: var(--ink); margin: 5px 0; transition: transform 0.2s, opacity 0.2s; }
.hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }
@media (max-width: 768px) {
    .hamburger { display: block; }
    .site-nav .nav-links,
    .landing-nav .nav-links {
        display: none; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0;
        background: var(--paper); border-bottom: 3px double var(--ink);
        padding: 1.5rem 2rem; gap: 1rem; text-align: center; z-index: 99;
    }
    .site-nav .nav-links.open,
    .landing-nav .nav-links.open { display: flex; }
}

/* ---- Site Footer ---- */
.site-footer {
    border-top: 2px solid var(--ink);
    padding: 2rem;
    text-align: center;
    font-size: 0.8rem;
    color: var(--ink-light);
}
.site-footer a { color: var(--ink-light); text-decoration: none; }
.site-footer a:hover { color: var(--accent); }

/* ---- Chart Card Grid ---- */
.chart-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.25rem; }
.chart-card {
    background: var(--surface);
    border: 1.5px solid var(--rule);
    border-radius: var(--radius);
    overflow: hidden;
    transition: box-shadow 0.15s, border-color 0.15s, transform 0.12s;
    display: flex;
    flex-direction: column;
}
.chart-card:hover { box-shadow: var(--shadow-md); border-color: var(--accent); transform: translateY(-1px); }
.chart-card:focus-within { box-shadow: var(--shadow-md); border-color: var(--accent); }
.chart-card a { text-decoration: none; color: inherit; }
.card-thumb {
    aspect-ratio: 16/10;
    background: var(--accent-soft);
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; position: relative;
}
.card-thumb svg { width: 100%; height: 100%; }
.card-thumb-placeholder { font-size: 2rem; color: var(--accent); opacity: 0.4; font-family: var(--font-serif); }
.card-type-badge {
    position: absolute; top: 0.5rem; right: 0.5rem;
    font-size: 0.62rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em;
    background: rgba(255,255,255,0.92); color: var(--ink-light);
    padding: 0.2rem 0.5rem; border-radius: var(--radius-sm);
}
.card-body { padding: 1rem 1.15rem 0.85rem; flex: 1; display: flex; flex-direction: column; gap: 0.35rem; }
.card-title { font-family: var(--font-serif); font-size: 1rem; font-weight: 400; color: var(--ink); line-height: 1.3; }
.card-author { font-size: 0.75rem; color: var(--ink-light); }
.card-author a { color: var(--ink-light); }
.card-author a:hover { color: var(--accent); text-decoration: underline; }
.card-description { font-size: 0.8rem; color: var(--ink-light); line-height: 1.5; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.card-footer { padding: 0.6rem 1.15rem; border-top: 1px solid var(--rule-light); display: flex; align-items: center; justify-content: space-between; font-size: 0.72rem; color: var(--ink-faint); }
.card-tags { display: flex; flex-wrap: wrap; gap: 0.3rem; margin-top: auto; padding-top: 0.5rem; }

/* ---- Pagination ---- */
.pagination { display: flex; gap: 0.4rem; align-items: center; margin-top: 2.5rem; flex-wrap: wrap; }
.pagination a, .pagination span {
    display: inline-block; padding: 0.45rem 0.85rem; font-size: 0.82rem;
    border: 1.5px solid var(--rule); border-radius: var(--radius);
    color: var(--ink-light); text-decoration: none; transition: border-color 0.12s, color 0.12s;
}
.pagination a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.pagination .current { border-color: var(--accent); color: var(--accent); font-weight: 600; }
.pagination .disabled { opacity: 0.3; cursor: default; pointer-events: none; }

/* ---- Empty State ---- */
.empty-state { text-align: center; padding: 5rem 2rem; color: var(--ink-light); }
.empty-state h2 { font-size: 1.5rem; margin-bottom: 0.75rem; color: var(--ink); }
.empty-state p { font-size: 0.95rem; margin-bottom: 1.5rem; }

/* ---- Admin Tables ---- */
.admin-table { width: 100%; border-collapse: collapse; background: var(--surface); border: 1.5px solid var(--rule); border-radius: var(--radius); }
.admin-table th {
    font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em;
    color: var(--ink-light); text-align: left; padding: 0.65rem 0.85rem; border-bottom: 2px solid var(--rule);
}
.admin-table td { font-size: 0.85rem; padding: 0.55rem 0.85rem; border-bottom: 1px solid var(--rule-light); }
.admin-table tr:last-child td { border-bottom: none; }

/* ---- Back Link ---- */
.back-link {
    display: inline-flex; align-items: center; gap: 0.3rem;
    font-size: 0.85rem; color: var(--ink-light); text-decoration: none;
    transition: color 0.12s; margin-bottom: 1rem;
}
.back-link:hover { color: var(--accent); text-decoration: none; }

/* ---- Responsive ---- */
@media (max-width: 600px) {
    h1 { font-size: 1.65rem; }
}