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

:root {
    --bg: #0b0f14;
    --surface: #0f172a;
    --surface-2: #111827;
    --border: rgba(255, 255, 255, 0.12);
    --border-strong: rgba(255, 255, 255, 0.20);
    --text: #f3f4f6;
    --muted: rgba(243, 244, 246, 0.64);
    --accent-bg: #ffffff;
    --accent-fg: #0b0f14;
    --danger: #ef4444;
    --shadow: 0 18px 55px rgba(0, 0, 0, 0.55);
    --radius: 18px;
    --focus: 0 0 0 3px rgba(255, 255, 255, 0.22);
}

html, body {
    height: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-container {
    width: 100%;
    max-width: 440px;
    animation: fadeIn 0.25s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-box {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 44px 38px;
    box-shadow: var(--shadow);
}

.logo {
    text-align: center;
    margin-bottom: 28px;
}

.logo h1 {
    color: var(--text);
    font-size: 22px;
    margin-bottom: 8px;
    font-weight: 900;
    letter-spacing: -0.3px;
}

.logo p {
    color: var(--muted);
    font-size: 13px;
    font-weight: 700;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    color: var(--muted);
    font-weight: 900;
    margin-bottom: 10px;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: 14px;
    font-size: 15px;
    transition: border-color 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
    background: var(--surface-2);
    color: var(--text);
}

.form-group input:focus {
    outline: none;
    border-color: var(--border-strong);
    box-shadow: var(--focus);
    background: rgba(255, 255, 255, 0.06);
}

button[type="submit"] {
    width: 100%;
    padding: 12px 14px;
    background: var(--accent-bg);
    color: var(--accent-fg);
    border: 1px solid var(--accent-bg);
    border-radius: 14px;
    font-size: 15px;
    font-weight: 900;
    cursor: pointer;
    transition: transform 0.12s ease, background 0.12s ease, border-color 0.12s ease;
    position: relative;
    overflow: hidden;
    margin-top: 10px;
}

button[type="submit"]:hover:not(:disabled) {
    transform: translateY(-2px);
    background: rgba(243, 244, 246, 0.92);
    border-color: rgba(243, 244, 246, 0.92);
}

button[type="submit"]:active:not(:disabled) {
    transform: translateY(0);
}

button[type="submit"]:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 3px solid rgba(11, 15, 20, 0.22);
    border-radius: 50%;
    border-top-color: rgba(11, 15, 20, 0.92);
    animation: spin 0.8s linear infinite;
    margin-left: 10px;
    vertical-align: middle;
}

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

.hidden {
    display: none !important;
}

.error-message {
    background: rgba(239, 68, 68, 0.14);
    border: 1px solid rgba(239, 68, 68, 0.45);
    color: rgba(254, 202, 202, 0.95);
    padding: 12px 16px;
    border-radius: 14px;
    margin-top: 15px;
    font-size: 14px;
    text-align: center;
    font-weight: 800;
}

.error-message.shake {
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    10%, 30%, 50%, 70%, 90% {
        transform: translateX(-5px);
    }
    20%, 40%, 60%, 80% {
        transform: translateX(5px);
    }
}

.footer {
    margin-top: 30px;
    text-align: center;
}

.footer p {
    color: var(--muted);
    font-size: 13px;
    font-weight: 700;
}

/* Responsive */
@media (max-width: 768px) {
    .login-box {
        padding: 36px 26px;
    }

    .logo h1 {
        font-size: 20px;
    }

    .logo p {
        font-size: 12px;
    }
}

@media (max-width: 480px) {
    .login-box {
        padding: 30px 20px;
    }

    .logo h1 {
        font-size: 18px;
    }
}