:root {
    --bg-primary: #ffffff;
    --bg-surface: rgba(255, 255, 255, 0.7);
    --text-main: #1e293b;
    --accent: #0f766e;
    --accent-hover: #115e59;
    --glass-border: rgba(255, 255, 255, 0.4);
    --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.05);
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-surface: rgba(30, 41, 59, 0.7);
    --text-main: #f8fafc;
    --accent: #14b8a6;
    --accent-hover: #2dd4bf;
    --glass-border: rgba(255, 255, 255, 0.1);
    --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

body {
    background-color: var(--bg-primary);
    color: var(--text-main);
    font-family: 'Plus Jakarta Sans', sans-serif;
    transition: background-color 0.4s ease, color 0.4s ease;
    overflow-x: hidden;
}

/* Preloader Screen */
#preloader {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: var(--bg-primary);
    z-index: 9999;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.spinner {
    width: 50px; height: 50px;
    border: 5px solid var(--glass-border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s infinite linear;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* Glassmorphism Premium Card */
.glass-card {
    background: var(--bg-surface);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    box-shadow: var(--shadow);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease;
}

.glass-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.12);
}

/* Custom Interactive Components */
.btn-premium {
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 12px 28px;
    font-weight: 600;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}

.btn-premium:hover {
    transform: scale(1.03);
    box-shadow: 0 8px 20px rgba(20, 184, 166, 0.3);
    color: #fff;
}