:root {
    --primary-start: #667eea;
    --primary-end: #764ba2;
    --primary-50: rgba(102, 126, 234, 0.05);
    --primary-100: rgba(102, 126, 234, 0.1);
    --primary-200: rgba(102, 126, 234, 0.2);
    --primary-400: rgba(102, 126, 234, 0.4);
    --surface: #ffffff;
    --surface-hover: #f8f9fc;
    --text-primary: #1a1f36;
    --text-secondary: #5a6072;
    --text-muted: #9098a8;
    --border: #e2e6ef;
    --border-focus: #667eea;
    --error-bg: #fef2f2;
    --error-border: #fecaca;
    --error-text: #dc2626;
    --success: #10b981;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-start) 0%, var(--primary-end) 100%);
    padding: 16px;
    position: relative;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 40%, rgba(255, 255, 255, 0.08) 0%, transparent 60%),
                radial-gradient(circle at 70% 60%, rgba(255, 255, 255, 0.06) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.login-container {
    width: 100%;
    max-width: 420px;
    position: relative;
    z-index: 1;
}

.login-box {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-lg);
    padding: 40px 32px;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

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

.logo-icon {
    width: 72px;
    height: 72px;
    background: linear-gradient(135deg, var(--primary-start) 0%, var(--primary-end) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    color: white;
    box-shadow: 0 8px 24px var(--primary-200);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.logo-icon:hover {
    transform: scale(1.05);
    box-shadow: 0 12px 32px var(--primary-400);
}

.login-title {
    font-size: 26px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 6px;
    letter-spacing: -0.5px;
}

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

.login-form {
    margin-top: 28px;
}

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

.form-label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

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

.input-icon {
    position: absolute;
    left: 14px;
    color: var(--text-muted);
    pointer-events: none;
    transition: color var(--transition-fast);
}

.form-input {
    width: 100%;
    padding: 14px 14px 14px 46px;
    border: 2px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 16px;
    transition: all var(--transition-fast);
    outline: none;
    background: var(--surface);
    color: var(--text-primary);
    -webkit-appearance: none;
    appearance: none;
    min-height: 48px;
}

.form-input:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 4px var(--primary-100);
}

.form-input:focus ~ .input-icon,
.input-wrapper:focus-within .input-icon {
    color: var(--primary-start);
}

.form-input::placeholder {
    color: var(--text-muted);
}

.toggle-password {
    position: absolute;
    right: 12px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 18px;
    padding: 8px;
    min-width: 40px;
    min-height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.5;
    transition: opacity var(--transition-fast);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
}

.toggle-password:hover {
    opacity: 1;
    background: var(--primary-50);
}

.error-message {
    background: var(--error-bg);
    border: 1px solid var(--error-border);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--error-text);
    font-size: 14px;
    animation: shake 0.4s cubic-bezier(0.36, 0.07, 0.19, 0.97);
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    15% { transform: translateX(-6px); }
    30% { transform: translateX(5px); }
    45% { transform: translateX(-4px); }
    60% { transform: translateX(3px); }
    75% { transform: translateX(-2px); }
}

.error-message svg {
    color: var(--error-text);
    flex-shrink: 0;
}

.login-btn {
    width: 100%;
    padding: 16px 24px;
    min-height: 52px;
    background: linear-gradient(135deg, var(--primary-start) 0%, var(--primary-end) 100%);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    letter-spacing: 1px;
    position: relative;
    overflow: hidden;
}

.login-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent 0%, rgba(255, 255, 255, 0.15) 100%);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.login-btn:hover:not(:disabled)::before {
    opacity: 1;
}

.login-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--primary-400);
}

.login-btn:active:not(:disabled) {
    transform: translateY(0);
}

.login-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2.5px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s cubic-bezier(0.6, 0, 0.4, 1) infinite;
}

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

.login-footer {
    text-align: center;
    margin-top: 28px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 12px;
}

@media (max-width: 480px) {
    body {
        padding: 12px;
        background: linear-gradient(160deg, var(--primary-start) 0%, var(--primary-end) 100%);
    }

    .login-box {
        padding: 32px 24px;
        border-radius: 16px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    }

    .logo-icon {
        width: 64px;
        height: 64px;
    }
    .logo-icon svg {
        width: 36px;
        height: 36px;
    }

    .login-title {
        font-size: 22px;
    }

    .form-input {
        padding: 12px 12px 12px 44px;
        font-size: 16px;
        min-height: 48px;
    }

    .login-btn {
        min-height: 48px;
        padding: 14px 24px;
        font-size: 15px;
    }

    .login-header {
        margin-bottom: 24px;
    }

    .login-form {
        margin-top: 24px;
    }

    .form-group {
        margin-bottom: 16px;
    }
}

@media (max-width: 360px) {
    body {
        padding: 8px;
    }

    .login-box {
        padding: 24px 16px;
        border-radius: 12px;
    }

    .logo-icon {
        width: 56px;
        height: 56px;
    }
    .logo-icon svg {
        width: 32px;
        height: 32px;
    }

    .login-title {
        font-size: 20px;
    }

    .login-subtitle {
        font-size: 13px;
    }
}

@media (max-height: 640px) and (orientation: landscape) {
    body {
        align-items: flex-start;
        padding: 12px;
    }

    .login-box {
        padding: 20px 24px;
    }

    .login-header {
        margin-bottom: 16px;
    }
    .logo-icon {
        width: 48px;
        height: 48px;
        margin-bottom: 8px;
    }
    .logo-icon svg {
        width: 28px;
        height: 28px;
    }
    .login-title {
        font-size: 20px;
    }
    .login-subtitle {
        font-size: 12px;
    }
    .form-group {
        margin-bottom: 12px;
    }
    .form-input {
        padding: 10px 12px 10px 40px;
        min-height: 42px;
        font-size: 15px;
    }
    .login-btn {
        min-height: 42px;
        padding: 10px 24px;
    }
    .login-form {
        margin-top: 16px;
    }
    .login-footer {
        margin-top: 16px;
        padding-top: 12px;
    }
}