:root {
    --bg-dark: #070B12;
    --bg-surface: #101726;
    --bg-surface-elevated: #182338;
    --bg-surface-active: #202e48;
    --border-color: #23314c;
    --border-color-light: #34486d;
    
    --color-primary: #DB0007; /* Arsenal Crimson */
    --color-primary-hover: #b80006;
    --color-gold: #9C824A;    /* Stadium Gold Accent */
    --color-gold-bright: #D4AF37;
    --color-accent-blue: #0284C7;
    --color-success: #10B981;
    --color-warning: #F59E0B;
    --color-danger: #EF4444;
    
    --text-main: #F8FAFC;
    --text-muted: #94A3B8;
    --text-dim: #64748B;
    
    --font-family-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-family-mono: "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;
    --font-family-display: "Arial Black", -apple-system, sans-serif;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-family-sans);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

/* Header */
.app-header {
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    padding: 12px 24px;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.stadium-badge {
    background-color: var(--color-primary);
    color: #fff;
    font-weight: 800;
    font-size: 11px;
    letter-spacing: 1px;
    padding: 3px 8px;
    border-radius: 4px;
}

.brand-title {
    font-weight: 700;
    font-size: 16px;
    letter-spacing: 0.5px;
}

.phase-tag {
    font-size: 11px;
    color: var(--color-gold-bright);
    background: rgba(156, 130, 74, 0.15);
    border: 1px solid rgba(156, 130, 74, 0.3);
    padding: 2px 6px;
    border-radius: 4px;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 6px;
    transition: all 0.15s ease;
}

.nav-link:hover {
    color: var(--text-main);
    background: var(--bg-surface-elevated);
}

.nav-link.active {
    color: #fff;
    background: var(--bg-surface-elevated);
    border: 1px solid var(--border-color-light);
}

.nav-display-link {
    color: var(--color-gold-bright);
    border: 1px solid rgba(212, 175, 55, 0.4);
}

.header-status {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    font-weight: 600;
    color: var(--color-success);
}

.status-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--color-success);
    box-shadow: 0 0 8px var(--color-success);
}

/* Main & Footer */
.app-main {
    flex: 1;
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
    padding: 24px;
}

.app-footer {
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    padding: 12px 24px;
    font-size: 12px;
    color: var(--text-dim);
}

.footer-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
}

/* Button System */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: inherit;
    font-size: 14px;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: 6px;
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.15s ease;
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background-color: var(--color-primary);
    color: #fff;
}
.btn-primary:hover { background-color: var(--color-primary-hover); }

.btn-outline {
    background: transparent;
    border-color: var(--border-color-light);
    color: var(--text-main);
}
.btn-outline:hover {
    background: var(--bg-surface-elevated);
}

.btn-danger {
    background-color: rgba(239, 68, 68, 0.15);
    border-color: var(--color-danger);
    color: #ff6b6b;
}
.btn-danger:hover {
    background-color: var(--color-danger);
    color: #fff;
}

.btn-block { width: 100%; }
.btn-sm { padding: 4px 10px; font-size: 12px; }
.btn-lg { padding: 12px 24px; font-size: 16px; }

/* Utilities */
.text-muted { color: var(--text-muted); }
.text-gold { color: var(--color-gold-bright); }