:root {
    --bg-gradient: linear-gradient(135deg, #0f172a, #1e293b);
    --bg-header-stripe: linear-gradient(135deg, #0ea5e9, #6366f1, #8b5cf6);
    --text-primary: #e2e8f0;
    --text-heading: #ffffff;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --card-bg: rgba(255,255,255,0.05);
    --card-bg-secondary: rgba(255,255,255,0.08);
    --card-border: rgba(255,255,255,0.1);
    --card-border-hover: rgba(148,163,184,0.3);
    --card-shadow: 0 8px 25px rgba(2,8,20,0.3);
    --card-shadow-lg: 0 8px 32px rgba(2,8,20,0.4);
    --input-bg: rgba(15,23,42,0.5);
    --input-bg-focus: rgba(15,23,42,0.7);
    --input-border: rgba(148,163,184,0.2);
    --primary-gradient: linear-gradient(135deg, #0ea5e9, #6366f1);
    --primary-shadow: 0 4px 15px rgba(14,165,233,0.3);
    --primary-shadow-hover: 0 6px 20px rgba(14,165,233,0.4);
    --btn-secondary-bg: rgba(255,255,255,0.05);
    --btn-secondary-bg-hover: rgba(255,255,255,0.1);
    --btn-secondary-border: rgba(255,255,255,0.2);
    --btn-secondary-border-hover: rgba(255,255,255,0.3);
    --btn-secondary-color: #cbd5e1;
    --success-color: #10b981;
    --error-color: #ef4444;
    --info-color: #0ea5e9;
    --disabled-btn-bg: #475569;
    --logo-text-shadow: 0 2px 10px rgba(0,0,0,0.2);
    --focus-ring: rgba(14,165,233,0.2);
    --password-toggle-color: #94a3b8;
    --password-toggle-hover-bg: rgba(255,255,255,0.1);
    --divider-color: rgba(255,255,255,0.1);
    --divider-color-light: rgba(255,255,255,0.05);
}

[data-theme="light"] {
    --bg-gradient: linear-gradient(135deg, #f1f5f9, #ffffff);
    --text-primary: #334155;
    --text-heading: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --card-bg: #f8fafc;
    --card-bg-secondary: #ffffff;
    --card-border: rgba(0,0,0,0.08);
    --card-border-hover: rgba(0,0,0,0.15);
    --card-shadow: 0 4px 12px rgba(0,0,0,0.06);
    --card-shadow-lg: 0 8px 32px rgba(0,0,0,0.1);
    --input-bg: #ffffff;
    --input-bg-focus: #ffffff;
    --input-border: rgba(0,0,0,0.12);
    --primary-shadow: 0 4px 15px rgba(14,165,233,0.2);
    --primary-shadow-hover: 0 6px 20px rgba(14,165,233,0.3);
    --btn-secondary-bg: #f1f5f9;
    --btn-secondary-bg-hover: #e2e8f0;
    --btn-secondary-border: rgba(0,0,0,0.1);
    --btn-secondary-border-hover: rgba(0,0,0,0.2);
    --btn-secondary-color: #475569;
    --disabled-btn-bg: #94a3b8;
    --logo-text-shadow: none;
    --focus-ring: rgba(14,165,233,0.15);
    --password-toggle-color: #64748b;
    --password-toggle-hover-bg: rgba(0,0,0,0.05);
    --divider-color: rgba(0,0,0,0.08);
    --divider-color-light: rgba(0,0,0,0.04);
}

* { box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0;
    background: var(--bg-gradient);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: var(--bg-header-stripe);
    z-index: -1;
    border-radius: 0 0 30px 30px;
}

.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    position: relative;
    z-index: 1;
}

.login-card {
    width: 100%;
    max-width: 500px;
    position: relative;
    background: var(--card-bg-secondary);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 24px;
    border: 1px solid var(--card-border);
    box-shadow: var(--card-shadow-lg);
    padding: 40px;
    animation: fadeIn 0.5s ease-out;
}

.login-header {
    text-align: center;
    margin-bottom: 40px;
}

.login-header h1 {
    color: var(--text-heading);
    margin: 0 0 10px 0;
    font-weight: 700;
    font-size: 32px;
    letter-spacing: -0.5px;
    position: relative;
    padding-bottom: 15px;
    text-shadow: var(--logo-text-shadow);
}

.login-header h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, #0ea5e9, #8b5cf6);
    border-radius: 2px;
}

.login-subtitle {
    color: var(--text-secondary);
    font-size: 1em;
    margin: 0;
    opacity: 0.8;
}

.language-selector {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-top: 20px;
}

.lang-btn {
    padding: 8px 24px;
    border: 1px solid var(--btn-secondary-border);
    border-radius: 20px;
    background: var(--btn-secondary-bg);
    color: var(--btn-secondary-color);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9em;
    font-weight: 500;
}

.lang-btn:hover {
    background: var(--btn-secondary-bg-hover);
    border-color: var(--btn-secondary-border-hover);
}

.lang-btn.active {
    background: var(--primary-gradient);
    border-color: transparent;
    color: white;
    box-shadow: var(--primary-shadow);
}

.input-group {
    margin-bottom: 30px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 0.95em;
}

.password-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.password-input-wrapper input {
    flex-grow: 1;
    padding: 16px 20px;
    padding-right: 50px;
    border: 1px solid var(--input-border);
    border-radius: 16px;
    font-size: 1em;
    transition: all 0.3s ease;
    background: var(--input-bg);
    color: var(--text-primary);
    box-shadow: var(--card-shadow);
}

.password-input-wrapper input:focus {
    outline: none;
    border-color: #0ea5e9;
    box-shadow: 0 0 0 3px var(--focus-ring);
    background: var(--input-bg-focus);
}

.password-toggle {
    position: absolute;
    right: 12px;
    background: transparent;
    border: none;
    color: var(--password-toggle-color);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.password-toggle:hover {
    color: var(--text-primary);
    background: var(--password-toggle-hover-bg);
}

.login-actions {
    margin-bottom: 20px;
}

.login-btn {
    width: 100%;
    padding: 16px 24px;
    border: none;
    border-radius: 16px;
    background: var(--primary-gradient);
    color: white;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    font-weight: 600;
    font-size: 1em;
    box-shadow: var(--primary-shadow);
    position: relative;
    overflow: hidden;
}

.login-btn::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transform: translateX(-100%);
    transition: transform 0.6s ease;
}

.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--primary-shadow-hover);
}

.login-btn:hover::after {
    transform: translateX(100%);
}

.login-btn:disabled {
    background: var(--disabled-btn-bg);
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.login-btn:disabled::after { display: none; }

.login-footer {
    text-align: center;
    margin-top: 20px;
}

.error-message {
    color: var(--error-color);
    font-size: 0.9em;
    min-height: 20px;
    margin: 10px 0 0 0;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.error-message.show { opacity: 1; }

.login-info {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 1px solid var(--divider-color);
}

.info-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 20px;
    border: 1px solid var(--divider-color-light);
}

.info-card h3 {
    color: var(--text-heading);
    margin: 0 0 10px 0;
    font-size: 1.1em;
    font-weight: 600;
}

.info-card p {
    color: var(--text-secondary);
    font-size: 0.9em;
    line-height: 1.5;
    margin: 0;
}

.login-theme-toggle {
    position: absolute;
    top: 16px;
    right: 16px;
    background: none;
    border: 1px solid var(--btn-secondary-border);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--btn-secondary-color);
    transition: all 0.3s ease;
    z-index: 1;
}

.login-theme-toggle:hover {
    background: var(--btn-secondary-bg);
    color: var(--text-primary);
    border-color: var(--btn-secondary-border-hover);
}

.login-theme-toggle svg { transition: transform 0.4s ease; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

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

.shake { animation: shake 0.5s ease-in-out; }

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}

@media (max-width: 768px) {
    .login-card { padding: 30px 20px; margin: 20px; }
    .login-header h1 { font-size: 28px; }
    body::before { height: 200px; }
}

@media (max-width: 480px) {
    .login-card { padding: 25px 15px; }
    .login-header h1 { font-size: 24px; }
}