:root {
    --primary: #1a2a6c;
    --primary-light: #2a3a8c;
    --primary-dark: #0f1a4a;
    --accent: #3a5ae8;
    --white: #ffffff;
    --light-gray: #f5f6fa;
    --gray: #6b7280;
    --dark: #1f2937;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--dark);
    background: var(--white);
    line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Navbar */
.navbar {
    background: rgba(26, 42, 108, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 20px rgba(0,0,0,0.2);
    border-bottom: 1px solid rgba(255,255,255,0.1);
}
.navbar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    z-index: -1;
}
.navbar .logo {
    color: var(--white);
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: 1px;
}
.navbar .logo span { color: var(--white); }
.navbar nav a {
    color: rgba(255,255,255,0.85);
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.2s;
}
.navbar nav a:hover { color: var(--white); text-decoration: none; }

/* Hero */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 6rem 2rem;
    text-align: center;
}
.hero h1 { font-size: 3rem; font-weight: 800; margin-bottom: 1rem; }
.hero p { font-size: 1.25rem; opacity: 0.9; max-width: 600px; margin: 0 auto 2rem; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}
.btn-primary { background: var(--accent); color: var(--white); }
.btn-primary:hover { background: #2a4ad8; color: var(--white); text-decoration: none; }
.btn-outline { background: transparent; color: var(--white); border: 2px solid var(--white); }
.btn-outline:hover { background: rgba(255,255,255,0.15); color: var(--white); text-decoration: none; }
.btn-danger { background: var(--danger); color: var(--white); }
.btn-danger:hover { background: #dc2626; color: var(--white); }
.btn-success { background: var(--success); color: var(--white); }
.btn-success:hover { background: #059669; color: var(--white); }
.btn-sm { padding: 0.4rem 1rem; font-size: 0.85rem; min-width: 70px; text-align: center; }

/* Sections */
.section {
    padding: 5rem 2rem;
    max-width: 1100px;
    margin: 0 auto;
}
.section-alt { background: var(--light-gray); }
.section-alt .section { padding: 5rem 2rem; }
.section h2 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
    text-align: center;
}
.section .subtitle {
    text-align: center;
    color: var(--gray);
    margin-bottom: 3rem;
    font-size: 1.1rem;
}

/* Cards */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 2rem; }
.card {
    background: var(--white);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    transition: transform 0.2s;
}
.card:hover { transform: translateY(-4px); }
.card .icon { font-size: 2.5rem; margin-bottom: 1rem; }
.card h3 { color: var(--primary); margin-bottom: 0.5rem; }
.card p { color: var(--gray); }

/* Footer */
.footer {
    background: var(--primary-dark);
    color: rgba(255,255,255,0.7);
    text-align: center;
    padding: 2rem;
    font-size: 0.9rem;
}

/* Forms */
.form-group { margin-bottom: 1.25rem; }
.form-group label { display: block; font-weight: 600; margin-bottom: 0.3rem; color: var(--dark); }
.form-group input, .form-group select {
    width: 100%;
    max-width: 100%;
    padding: 0.65rem 1rem;
    border: 1.5px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
    box-sizing: border-box;
}
.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(58,90,232,0.1);
}

/* Login card */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--light-gray);
}
.login-card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
}
.login-card h1 { text-align: center; color: var(--primary); margin-bottom: 0.5rem; }
.login-card .subtitle { text-align: center; color: var(--gray); margin-bottom: 2rem; }
.login-card .btn { width: 100%; }

/* Alert */
.alert {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}
.alert-error { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: var(--success); border: 1px solid #bbf7d0; }


/* Mobile */
@media (max-width: 768px) {
    .navbar { padding: 0.75rem 1rem; gap: 0.5rem; }
    .navbar .logo { font-size: 1.1rem; }
    .navbar .logo .logo-gym { display: none; }
    .navbar nav a { margin-left: 0.75rem; font-size: 0.85rem; }
    .hero { padding: 3rem 1.5rem; }
    .hero h1 { font-size: 2rem; }
    .hero p { font-size: 1rem; }
    .btn { padding: 0.6rem 1.2rem; font-size: 0.9rem; }
    .section { padding: 3rem 1rem; }
    .form-group input[type="date"] { width: 80%; }
}