/**
 * GEOAir Modern UI - Light Theme Design System
 * White surfaces, restrained blue accents, and clear text hierarchy
 */

:root {
    /* --- Surface Layers: White and cool gray surfaces --- */
    --surface-0: #f5f7fa;
    --surface-1: #ffffff;
    --surface-2: #ffffff;
    --surface-3: #f1f5f9;
    --surface-4: #dce3ec;
    --surface-5: #c4cedb;

    /* --- Accent: Clear blue accent --- */
    --accent-primary: #0077b6;
    --accent-primary-hover: #0369a1;
    --accent-muted: #e0f2fe;

    /* --- Text Hierarchy --- */
    --text-primary: #172033;
    --text-secondary: #475569;
    --text-tertiary: #64748b;
    --text-dim: #64748b;

    /* --- Semantic Colors --- */
    --success: #047857;
    --warning: #b45309;
    --error: #be123c;
    --info: #0077b6;

    /* --- Border & Divider --- */
    --border-subtle: rgba(148, 163, 184, 0.1);
    --border-default: rgba(148, 163, 184, 0.15);
    --border-strong: rgba(148, 163, 184, 0.25);

    /* --- Shadows --- */
    --shadow-sm: 0 1px 2px 0 rgba(23, 32, 51, 0.04);
    --shadow-md: 0 4px 12px 0 rgba(23, 32, 51, 0.06);
    --shadow-lg: 0 20px 40px -12px rgba(23, 32, 51, 0.08);

    /* --- Radius: Full round --- */
    --radius-pill: 999px;
    --radius-full: 50%;
    --radius-card: 16px;
    --radius-control: 12px;

    /* --- Spacing Scale --- */
    --spacing-xs: 0.5rem;   /* 8px */
    --spacing-sm: 0.75rem;  /* 12px */
    --spacing-md: 1rem;     /* 16px */
    --spacing-lg: 1.5rem;   /* 24px */
    --spacing-xl: 2rem;     /* 32px */
    --spacing-2xl: 3rem;    /* 48px */

    /* --- Typography --- */
    --font-sans: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', 'PingFang SC', 'Noto Sans SC', sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Monaco, 'Cascadia Code', 'Source Code Pro', Consolas, monospace;

    /* --- Fluid Type Scale --- */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
    --text-base: clamp(1rem, 0.9rem + 0.5vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.625vw, 1.375rem);
    --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.75rem);
    --text-2xl: clamp(1.5rem, 1.25rem + 1.25vw, 2.25rem);
    --text-3xl: clamp(1.875rem, 1.5rem + 1.875vw, 3rem);
    --text-4xl: clamp(2.25rem, 1.75rem + 2.5vw, 3.75rem);

    /* --- Line Heights --- */
    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.75;

    /* --- Letter Spacing --- */
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
}

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

body.geoair-modern {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--text-primary);
    background: var(--surface-0);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --- Typography --- */
.geoair-modern h1,
.geoair-modern h2,
.geoair-modern h3,
.geoair-modern h4 {
    letter-spacing: var(--tracking-tight);
    line-height: var(--leading-tight);
    font-weight: 600;
}

.geoair-modern h1 { font-size: var(--text-4xl); }
.geoair-modern h2 { font-size: var(--text-3xl); }
.geoair-modern h3 { font-size: var(--text-2xl); }
.geoair-modern h4 { font-size: var(--text-xl); }

.geoair-modern p {
    line-height: var(--leading-relaxed);
}

/* --- Site Header (Front) --- */
.geoair-header {
    background: var(--surface-1);
    border-bottom: 1px solid var(--border-subtle);
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: blur(12px);
}

.geoair-header__container {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: var(--spacing-xl);
    max-width: 1280px;
    margin: 0 auto;
    padding: var(--spacing-md) var(--spacing-lg);
}

.geoair-header__brand {
    font-size: var(--text-xl);
    font-weight: 700;
    letter-spacing: var(--tracking-tight);
    color: var(--text-primary);
    text-decoration: none;
    transition: color 200ms ease;
}

.geoair-header__brand:hover {
    color: var(--accent-primary);
}

.geoair-header__nav {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.geoair-header__nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: var(--text-sm);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-control);
    transition: all 200ms ease;
}

.geoair-header__nav a:hover,
.geoair-header__nav a.active {
    color: var(--accent-primary);
    background: var(--surface-3);
}

/* --- Hero Section --- */
.geoair-hero {
    background: linear-gradient(180deg, var(--surface-1) 0%, var(--surface-2) 100%);
    padding: clamp(3rem, 8vw, 6rem) var(--spacing-lg);
    border-bottom: 1px solid var(--border-subtle);
}

.geoair-hero__content {
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
}

.geoair-hero__title {
    font-size: var(--text-4xl);
    font-weight: 700;
    letter-spacing: var(--tracking-tight);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.geoair-hero__subtitle {
    font-size: var(--text-lg);
    color: var(--text-secondary);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--spacing-xl);
}

.geoair-hero__search {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: var(--spacing-sm);
    max-width: 560px;
    margin: 0 auto;
}

.geoair-hero__search input {
    background: var(--surface-3);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-pill);
    padding: 0.75rem 1.5rem;
    color: var(--text-primary);
    font-size: var(--text-sm);
    outline: none;
    transition: all 200ms ease;
}

.geoair-hero__search input::placeholder {
    color: var(--text-dim);
}

.geoair-hero__search input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

.geoair-hero__search button {
    background: var(--accent-primary);
    color: #ffffff;
    border: none;
    border-radius: var(--radius-pill);
    padding: 0.75rem 2rem;
    font-size: var(--text-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all 200ms ease;
}

.geoair-hero__search button:hover {
    background: var(--accent-primary-hover);
    transform: translateY(-1px);
}

/* --- Article Grid --- */
.geoair-articles {
    max-width: 1280px;
    margin: 0 auto;
    padding: var(--spacing-2xl) var(--spacing-lg);
}

.geoair-articles__grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-xl);
}

/* --- Article Card --- */
.geoair-card {
    background: var(--surface-2);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-card);
    padding: var(--spacing-lg);
    transition: all 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

.geoair-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-muted);
    box-shadow: var(--shadow-lg);
}

.geoair-card__meta {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.geoair-card__badge {
    background: var(--accent-muted);
    color: var(--accent-primary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-pill);
    font-size: var(--text-xs);
    font-weight: 600;
}

.geoair-card__date {
    color: var(--text-tertiary);
    font-size: var(--text-xs);
}

.geoair-card__title {
    font-size: var(--text-xl);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    letter-spacing: var(--tracking-tight);
}

.geoair-card__excerpt {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--spacing-md);
}

.geoair-card__link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent-primary);
    font-size: var(--text-sm);
    font-weight: 500;
    text-decoration: none;
    transition: gap 200ms ease;
}

.geoair-card__link:hover {
    gap: 0.75rem;
}

/* --- Admin Login Page --- */
.geoair-login {
    min-height: 100vh;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, var(--surface-0) 0%, var(--surface-1) 50%, var(--surface-2) 100%);
    padding: var(--spacing-lg);
}

.geoair-login__card {
    background: var(--surface-2);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-card);
    padding: var(--spacing-2xl);
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-lg);
}

.geoair-login__header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.geoair-login__logo {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--spacing-md);
    background: var(--accent-primary);
    border-radius: var(--radius-full);
    display: grid;
    place-items: center;
}

.geoair-login__title {
    font-size: var(--text-2xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.geoair-login__subtitle {
    font-size: var(--text-sm);
    color: var(--text-secondary);
}

.geoair-login__form {
    display: grid;
    gap: var(--spacing-lg);
}

.geoair-form-field {
    display: grid;
    gap: var(--spacing-xs);
}

.geoair-form-field label {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--text-secondary);
}

.geoair-form-field input {
    background: var(--surface-3);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-control);
    padding: 0.875rem 1rem;
    color: var(--text-primary);
    font-size: var(--text-sm);
    outline: none;
    transition: all 200ms ease;
}

.geoair-form-field input:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
    background: var(--surface-4);
}

.geoair-login__button {
    background: var(--accent-primary);
    color: #ffffff;
    border: none;
    border-radius: var(--radius-pill);
    padding: 1rem;
    font-size: var(--text-base);
    font-weight: 600;
    cursor: pointer;
    transition: all 200ms ease;
}

.geoair-login__button:hover {
    background: var(--accent-primary-hover);
    transform: translateY(-1px);
}

.geoair-login__footer {
    text-align: center;
    margin-top: var(--spacing-lg);
    font-size: var(--text-sm);
    color: var(--text-tertiary);
}

.geoair-login__footer a {
    color: var(--accent-primary);
    text-decoration: none;
}

/* --- Admin Dashboard --- */
.geoair-dashboard {
    background: var(--surface-0);
    min-height: 100vh;
}

.geoair-dashboard__header {
    background: var(--surface-1);
    border-bottom: 1px solid var(--border-subtle);
    padding: var(--spacing-xl) var(--spacing-lg);
}

.geoair-dashboard__title {
    font-size: var(--text-3xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.geoair-dashboard__subtitle {
    font-size: var(--text-base);
    color: var(--text-secondary);
}

.geoair-dashboard__content {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-lg);
}

.geoair-dashboard__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

/* --- Dashboard Card --- */
.geoair-dash-card {
    background: var(--surface-2);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-card);
    padding: var(--spacing-lg);
    transition: all 200ms ease;
}

.geoair-dash-card:hover {
    border-color: var(--border-default);
}

.geoair-dash-card__header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

.geoair-dash-card__icon {
    width: 40px;
    height: 40px;
    background: var(--accent-muted);
    color: var(--accent-primary);
    border-radius: var(--radius-full);
    display: grid;
    place-items: center;
}

.geoair-dash-card__label {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    font-weight: 500;
}

.geoair-dash-card__value {
    font-size: var(--text-3xl);
    color: var(--text-primary);
    font-weight: 700;
    margin-top: var(--spacing-xs);
}

.geoair-dash-card__meta {
    font-size: var(--text-xs);
    color: var(--text-tertiary);
    margin-top: var(--spacing-sm);
}

/* --- Article List Table --- */
.geoair-table-container {
    background: var(--surface-2);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-card);
    overflow: hidden;
}

.geoair-table {
    width: 100%;
    border-collapse: collapse;
}

.geoair-table thead {
    background: var(--surface-3);
    border-bottom: 1px solid var(--border-subtle);
}

.geoair-table th {
    text-align: left;
    padding: var(--spacing-md);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
}

.geoair-table td {
    padding: var(--spacing-md);
    font-size: var(--text-sm);
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-subtle);
}

.geoair-table tbody tr {
    transition: background-color 200ms ease;
}

.geoair-table tbody tr:hover {
    background: var(--surface-3);
}

/* --- Buttons --- */
.geoair-btn {
    border-radius: var(--radius-pill);
    padding: 0.75rem 1.5rem;
    font-size: var(--text-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all 200ms ease;
    border: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.geoair-btn--primary {
    background: var(--accent-primary);
    color: #ffffff;
}

.geoair-btn--primary:hover {
    background: var(--accent-primary-hover);
    transform: translateY(-1px);
}

.geoair-btn--secondary {
    background: var(--surface-3);
    color: var(--text-primary);
    border: 1px solid var(--border-default);
}

.geoair-btn--secondary:hover {
    background: var(--surface-4);
    border-color: var(--accent-muted);
}

/* --- Footer --- */
.geoair-footer {
    background: var(--surface-1);
    border-top: 1px solid var(--border-subtle);
    padding: var(--spacing-xl) var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.geoair-footer__content {
    max-width: 1280px;
    margin: 0 auto;
    text-align: center;
    color: var(--text-tertiary);
    font-size: var(--text-sm);
}

.geoair-footer__content a {
    color: var(--accent-primary);
    text-decoration: none;
}

/* --- Utility Classes --- */
.geoair-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.geoair-surface-0 { background: var(--surface-0); }
.geoair-surface-1 { background: var(--surface-1); }
.geoair-surface-2 { background: var(--surface-2); }
.geoair-surface-3 { background: var(--surface-3); }
.geoair-surface-4 { background: var(--surface-4); }
.geoair-surface-5 { background: var(--surface-5); }

.geoair-text-primary { color: var(--text-primary); }
.geoair-text-secondary { color: var(--text-secondary); }
.geoair-text-tertiary { color: var(--text-tertiary); }
.geoair-text-dim { color: var(--text-dim); }

.geoair-accent { color: var(--accent-primary); }
.geoair-accent-bg { background: var(--accent-primary); }

/* --- Responsive --- */
@media (max-width: 768px) {
    .geoair-header__nav {
        display: none;
    }

    .geoair-articles__grid {
        grid-template-columns: 1fr;
    }

    .geoair-dashboard__grid {
        grid-template-columns: 1fr;
    }

    .geoair-hero__search {
        grid-template-columns: 1fr;
    }
}