/* --- Variables & Core --- */
:root {
    --bg-color: #0f172a;       /* Deep Navy Background */
    --card-bg: #131c31;        /* Slightly Lighter Navy */
    --primary-blue: #38bdf8;   /* Sky Blue Accent */
    --primary-hover: #0ea5e9;  /* Darker Blue for Hover */
    --text-main: #ffffff;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body.light-mode {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #cbd5e1;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* --- Layout Elements --- */

.theme-toggle {
    position: absolute;
    top: 2rem;
    right: 2rem;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    transition: color 0.3s ease, transform 0.2s ease;
}

.theme-toggle:hover {
    color: var(--text-main);
    transform: scale(1.1);
}

.brand-logo {
    position: absolute;
    bottom: 2rem;
    left: 2rem;
    width: 40px;
    height: 40px;
    background-color: #000;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1.2rem;
    color: white;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body.light-mode .brand-logo {
    background-color: #ffffff;
    color: #000;
    border: 1px solid var(--border-color);
}

/* --- Main Card --- */
.login-card {
    background-color: transparent; 
    width: 100%;
    max-width: 450px;
    padding: 3rem 2rem;
    border-radius: 16px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.05); 
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
    transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

body.light-mode .login-card {
    border-color: rgba(0, 0, 0, 0.1);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.1);
}

.login-card h1 {
    font-size: 1.8rem;
    margin-bottom: 0.75rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.login-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 2.5rem;
}

/* --- Buttons --- */
.btn-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 0.85rem 1.5rem;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
    border: none;
}

.btn-primary {
    background-color: var(--primary-blue);
    color: #0f172a;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn-outline:hover {
    background-color: rgba(255, 255, 255, 0.03);
    border-color: var(--text-muted);
}

body.light-mode .btn-outline:hover {
    background-color: rgba(0, 0, 0, 0.03);
    border-color: #64748b;
}

.btn svg {
    margin-left: 0.5rem;
    width: 18px;
    height: 18px;
    transition: transform 0.2s;
}

.btn:hover svg {
    transform: translateX(4px);
}