/* ==========================================================================
   1. CSS VARIABLES (DESIGN SYSTEM - LIGHT & DARK THEMES)
   ================================================================---------- */

/* Default: Light Theme Variables */
:root {
    --bg-main: #f8fafc;
    --bg-surface: #ffffff;
    --bg-surface-solid: #f1f5f9;
    --bg-navbar: rgba(255, 255, 255, 0.85);
    --bg-footer: #f1f5f9;
    --text-main: #0f172a;
    --text-subdued: #475569;
    --text-light: #64748b;
    --primary-color: #0ea5e9;
    --primary-hover: #0284c7;
    --secondary-color: #6366f1;
    --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    --gradient-hover: linear-gradient(135deg, var(--primary-hover) 0%, #4f46e5 100%);
    --gradient-text: linear-gradient(135deg, #0284c7 0%, #4f46e5 100%);
    --border-glass: rgba(0, 0, 0, 0.08);
    --border-glow: rgba(14, 165, 233, 0.3);
    --border-subtle: rgba(0, 0, 0, 0.05);
    --shadow-glass: 0 10px 30px -10px rgba(0, 0, 0, 0.08);
    --shadow-btn: 0 4px 20px rgba(14, 165, 233, 0.3);
    --backdrop-blur: blur(16px);
}

/* Dark Theme Variables (Activable con [data-theme="dark"] o clase .dark-mode) */
[data-theme="dark"], .dark-mode {
    --bg-main: #030712;
    --bg-surface: rgba(17, 24, 39, 0.8);
    --bg-surface-solid: #111827;
    --bg-navbar: rgba(3, 7, 18, 0.85);
    --bg-footer: rgba(3, 7, 18, 0.95);
    --text-main: #e2e8f0;
    --text-subdued: #cbd5e1;
    --text-light: #94a3b8;
    --border-glass: rgba(255, 255, 255, 0.08);
    --border-glow: rgba(14, 165, 233, 0.4);
    --border-subtle: rgba(255, 255, 255, 0.05);
    --shadow-glass: 0 20px 40px -15px rgba(14, 165, 233, 0.2);
    --shadow-btn: 0 4px 20px rgba(14, 165, 233, 0.4);
    --gradient-text: linear-gradient(135deg, #38bdf8 0%, #818cf8 100%);
}

/* ==========================================================================
   2. GENERAL STYLES & RESET
   ================================================================---------- */
html {
    scroll-padding-top: 90px;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    overflow-x: hidden;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* ==========================================================================
   3. BACKGROUND GLOW EFFECTS
   ================================================================---------- */
.bg-glow {
    position: absolute;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(14, 165, 233, 0.15) 0%, rgba(3, 7, 18, 0) 70%);
    z-index: 0;
    pointer-events: none;
}

/* ==========================================================================
   4. GLASSMORPHISM COMPONENTS (Tarjetas y Paneles)
   ================================================================---------- */
.glass-card {
    background: var(--bg-surface);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    border: 1px solid var(--border-glass);
    transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

    .glass-card:hover {
        transform: translateY(-4px);
        border-color: var(--border-glow);
        box-shadow: var(--shadow-glass);
    }

/* ==========================================================================
   5. BUTTONS & UTILITIES
   ================================================================---------- */
.btn-glow {
    background: var(--gradient-primary);
    border: none;
    color: #ffffff;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-btn);
}

    .btn-glow:hover {
        background: var(--gradient-hover);
        box-shadow: 0 6px 25px rgba(14, 165, 233, 0.6);
        color: #ffffff;
        transform: translateY(-2px);
    }

.btn-glass-outline {
    background: var(--bg-surface);
    border: 1px solid var(--border-glass);
    color: var(--text-main);
    transition: all 0.3s ease;
}

    .btn-glass-outline:hover {
        background: var(--bg-surface-solid);
        border-color: var(--primary-color);
        color: var(--primary-color);
    }

.text-gradient {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.text-subdued {
    color: var(--text-subdued) !important;
}

/* ==========================================================================
   6. NAVBAR & FOOTER CUSTOM STRUCTURES
   ================================================================---------- */
.navbar-fixed-custom {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1030;
    background: var(--bg-navbar);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    border-bottom: 1px solid var(--border-subtle);
    height: 80px;
    display: flex;
    align-items: center;
}

.footer-custom {
    background: var(--bg-footer);
    border-top: 1px solid var(--border-subtle);
    padding: 2rem 0;
    margin-top: auto;
}