/* ==========================================================================
   THEME VARIABLES (Default: Light Mode)
   ========================================================================== */
:root {
    --bg-main: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: rgba(0, 0, 0, 0.06);
    --input-bg: #ffffff;
    --glow-color: rgba(251, 36, 36, 0.12);
    --card-shadow: 0 20px 40px rgba(15, 23, 42, 0.08), 0 1px 3px rgba(0, 0, 0, 0.02);
    
    /* Global Brand Color */
    --primary-red: #fb2424;
    --hover-red: #dc2626;
    --title-gradient: linear-gradient(to bottom, #0f172a 60%, #64748b);
}

/* ==========================================================================
   DARK MODE VARIABLES (Second Mode)
   ========================================================================== */
[data-theme="dark"] {
    --bg-main: #0f172a;
    --card-bg: #1e293b;
    --text-main: #ffffff;
    --text-muted: #94a3b8;
    --border-color: rgba(255, 255, 255, 0.05);
    --input-bg: rgba(15, 23, 42, 0.6);
    --glow-color: rgba(251, 36, 36, 0.22);
    --card-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    --title-gradient: linear-gradient(to bottom, #ffffff 60%, #94a3b8);
}

/* ==========================================================================
   BASE & LAYOUT STYLES
   ========================================================================== */
body {
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: 'Poppins', sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    position: relative;
    margin: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Ambient Glow Behind Card */
body::before {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: var(--glow-color);
    border-radius: 50%;
    filter: blur(90px);
    top: 25%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 0;
    transition: background 0.3s ease;
}

/* Floating Theme Toggle Button */
.theme-toggle-btn {
    position: absolute;
    top: 25px;
    right: 25px;
    z-index: 10;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
}

.theme-toggle-btn:hover {
    transform: scale(1.08);
    border-color: var(--primary-red);
}

.content-container {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 480px;
    padding: 20px;
    text-align: center;
}

/* Hero Section */
#hero-section {
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.big-title {
    font-size: 4.5rem;
    font-weight: 800;
    letter-spacing: 4px;
    margin-bottom: 25px;
    background: var(--title-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 4px 15px rgba(0,0,0,0.05);
}

/* Login Card Section */
#login-form-section {
    display: none;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.login-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px 30px;
    box-shadow: var(--card-shadow);
    border-top: 4px solid var(--primary-red);
    transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

/* Custom Tabs Platform */
.nav-tabs {
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 30px;
}

.nav-tabs .nav-link {
    color: var(--text-muted);
    border: none;
    background: transparent;
    font-weight: 600;
    padding: 10px 30px;
    transition: 0.3s;
}

.nav-tabs .nav-link:hover {
    color: var(--text-main);
}

.nav-tabs .nav-link.active {
    color: var(--primary-red) !important;
    background: transparent;
    border-bottom: 3px solid var(--primary-red);
}

/* Form Controls */
.form-control {
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 14px 16px;
    border-radius: 10px;
    transition: all 0.3s ease;
}

.form-control:focus {
    background-color: var(--card-bg);
    border-color: var(--primary-red);
    box-shadow: 0 0 0 3px rgba(251, 36, 36, 0.15);
    color: var(--text-main);
}

/* Buttons Styling */
.btn-main {
    background: var(--primary-red);
    color: #ffffff;
    border: none;
    font-weight: 600;
    letter-spacing: 1px;
    padding: 14px 30px;
    border-radius: 10px;
    width: 100%;
    transition: 0.3s ease;
    box-shadow: 0 4px 15px rgba(251, 36, 36, 0.2);
}

.btn-main:hover {
    background: var(--hover-red);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(251, 36, 36, 0.35);
    color: #ffffff;
}

.btn-main:active {
    transform: translateY(0);
}