:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --border-color: rgba(255, 255, 255, 0.1);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --error-bg: rgba(239, 68, 68, 0.15);
    --error-border: #ef4444;
    --error-text: #fca5a5;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    background-image: 
        radial-gradient(at 0% 0%, rgba(59, 130, 246, 0.15) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(147, 51, 234, 0.15) 0px, transparent 50%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px;
    width: 100%;
    max-width: 420px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    transition: transform 0.2s ease;
}

.header {
    text-align: center;
    margin-bottom: 32px;
}

.logo {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.logo svg {
    width: 28px;
    height: 28px;
    fill: currentColor;
}

h1 {
    color: var(--text-main);
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 6px;
}

p.subtitle {
    color: var(--text-muted);
    font-size: 14px;
}

.alert {
    display: none;
    background: var(--error-bg);
    border: 1px solid var(--error-border);
    color: var(--error-text);
    padding: 12px 14px;
    border-radius: 8px;
    font-size: 13.5px;
    margin-bottom: 20px;
    align-items: center;
    gap: 10px;
    animation: fadeIn 0.3s ease;
}

.alert.active {
    display: flex;
}

.alert-svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.shake {
    animation: shake 0.4s cubic-bezier(.36,.07,.19,.97) both;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    color: var(--text-main);
    font-size: 13.5px;
    font-weight: 500;
    margin-bottom: 8px;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 12px 14px;
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-main);
    font-size: 14px;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="text"]:focus,
input[type="password"]:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25);
}

.options-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
    font-size: 13px;
}

.remember-me {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    cursor: pointer;
}

.remember-me input {
    cursor: pointer;
    accent-color: var(--primary);
}

.forgot-pass {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s;
}

.forgot-pass:hover {
    text-decoration: underline;
}

button.btn-submit {
    width: 100%;
    padding: 12px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 14.5px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

button.btn-submit:hover {
    background: var(--primary-hover);
}

button.btn-submit:active {
    transform: scale(0.99);
}

.spinner {
    display: none;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
}

.footer {
    margin-top: 28px;
    text-align: center;
    font-size: 12px;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    padding-top: 18px;
}

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

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes shake {
    10%, 90% { transform: translate3d(-1px, 0, 0); }
    20%, 80% { transform: translate3d(2px, 0, 0); }
    30%, 50%, 70% { transform: translate3d(-3px, 0, 0); }
    40%, 60% { transform: translate3d(3px, 0, 0); }
}