/**
 * iOS Native Login - Dark Theme Design System
 * Based on Apple's iOS Human Interface Guidelines
 */

/* ============================================
   1. CSS Variables - iOS Dark Theme
   ============================================ */
:root {
    /* Canvas & Surfaces */
    --bg-canvas: #000000;      /* True Black for OLED */
    --bg-surface: #1C1C1E;     /* System Gray 6 */
    --bg-secondary: #2C2C2E;   /* System Gray 5 */
    --bg-tertiary: #3A3A3C;    /* System Gray 4 */
    
    /* Semantic Colors */
    --color-primary: #30D158;  /* System Green - Primary Action */
    --color-alert: #FF453A;    /* System Red - Destructive/Anchor */
    --color-info: #0A84FF;     /* System Blue - Links */
    --color-warning: #FF9F0A;  /* System Orange */
    
    /* Text Colors */
    --text-primary: #FFFFFF;
    --text-secondary: #8E8E93; /* System Gray */
    --text-tertiary: #636366;  /* System Gray 2 */
    
    /* Typography - SF Pro */
    --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "Helvetica Neue", sans-serif;
    
    /* Spacing */
    --space-xs: 8px;
    --space-sm: 12px;
    --space-md: 16px;
    --space-lg: 20px;
    --space-xl: 24px;
    --space-xxl: 32px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-pill: 9999px;
    
    /* Safe Areas for iPhone X+ */
    --safe-area-top: env(safe-area-inset-top, 0px);
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.2s ease;
    
    /* Glassmorphism */
    --glass-bg: rgba(30, 30, 30, 0.85);
    --glass-blur: blur(20px);
    --glass-border: 0.5px solid rgba(255, 255, 255, 0.1);
}

/* ============================================
   2. Base Reset & Global Styles
   ============================================ */
* {
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    background-color: var(--bg-canvas);
    color: var(--text-primary);
    font-family: var(--font-family);
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   3. Login Container
   ============================================ */
.login-container {
    width: 100%;
    max-width: 400px;
    padding: var(--space-lg);
    padding-top: calc(var(--space-lg) + var(--safe-area-top));
    padding-bottom: calc(var(--space-lg) + var(--safe-area-bottom));
}

/* ============================================
   4. Header/Branding
   ============================================ */
.login-header {
    text-align: center;
    margin-bottom: var(--space-xxl);
}

.org-label {
    color: var(--color-alert);
    text-transform: uppercase;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-xs);
}

.app-title {
    font-size: 34px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin: 0;
    line-height: 1.1;
    color: var(--text-primary);
}

/* ============================================
   5. Login Card (Glassmorphic)
   ============================================ */
.login-card {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-radius: var(--radius-lg);
    border: var(--glass-border);
    padding: var(--space-xl);
    margin-bottom: var(--space-lg);
}

/* ============================================
   6. Form Elements
   ============================================ */
.form-group {
    margin-bottom: var(--space-lg);
}

.form-group:last-child {
    margin-bottom: 0;
}

.form-label {
    display: block;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    margin-bottom: var(--space-xs);
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.form-input {
    width: 100%;
    background-color: var(--bg-secondary);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    padding: var(--space-md);
    font-size: 17px;
    font-family: var(--font-family);
    color: var(--text-primary);
    transition: border-color var(--transition-normal), background-color var(--transition-normal);
    -webkit-appearance: none;
    appearance: none;
}

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

.form-input:focus {
    outline: none;
    border-color: var(--color-primary);
    background-color: var(--bg-tertiary);
}

/* ============================================
   7. Buttons
   ============================================ */
.btn-primary {
    width: 100%;
    background-color: var(--color-primary);
    color: #000000;
    border: none;
    border-radius: var(--radius-pill);
    padding: var(--space-md) var(--space-xl);
    font-size: 17px;
    font-weight: 600;
    font-family: var(--font-family);
    cursor: pointer;
    transition: opacity var(--transition-normal), transform var(--transition-fast);
    box-shadow: 0 4px 12px rgba(48, 209, 88, 0.3);
    margin-top: var(--space-lg);
}

.btn-primary:hover {
    opacity: 0.9;
}

.btn-primary:active {
    opacity: 0.7;
    transform: scale(0.98);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    width: 100%;
    background-color: var(--bg-secondary);
    color: var(--color-info);
    border: none;
    border-radius: var(--radius-pill);
    padding: var(--space-md) var(--space-xl);
    font-size: 15px;
    font-weight: 500;
    font-family: var(--font-family);
    cursor: pointer;
    transition: background-color var(--transition-normal);
}

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

.btn-secondary:active {
    background-color: var(--bg-tertiary);
}

/* ============================================
   8. Messages & Notifications
   ============================================ */
.message {
    padding: var(--space-md);
    border-radius: var(--radius-md);
    font-size: 14px;
    text-align: center;
    margin-bottom: var(--space-lg);
    display: none;
}

.message.error {
    background-color: rgba(255, 69, 58, 0.15);
    color: var(--color-alert);
    border: 1px solid rgba(255, 69, 58, 0.3);
    display: block;
}

.message.warning {
    background-color: rgba(255, 159, 10, 0.15);
    color: var(--color-warning);
    border: 1px solid rgba(255, 159, 10, 0.3);
    display: block;
}

.message.success {
    background-color: rgba(48, 209, 88, 0.15);
    color: var(--color-primary);
    border: 1px solid rgba(48, 209, 88, 0.3);
    display: block;
}

/* ============================================
   9. Loading Indicator
   ============================================ */
.loading-indicator {
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--space-md);
    color: var(--text-secondary);
    font-size: 15px;
}

.loading-indicator.visible {
    display: flex;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--bg-tertiary);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-right: var(--space-sm);
}

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

/* ============================================
   10. Responsive Adjustments
   ============================================ */
@media (max-width: 480px) {
    .login-container {
        padding: var(--space-md);
        padding-top: calc(var(--space-xl) + var(--safe-area-top));
        padding-bottom: calc(var(--space-xl) + var(--safe-area-bottom));
    }
    
    .app-title {
        font-size: 28px;
    }
    
    .login-card {
        padding: var(--space-lg);
    }
}

/* ============================================
   11. Safe Area Support for notched devices
   ============================================ */
@supports (padding: max(0px)) {
    .login-container {
        padding-top: max(var(--space-lg), calc(var(--space-lg) + var(--safe-area-top)));
        padding-bottom: max(var(--space-lg), calc(var(--space-lg) + var(--safe-area-bottom)));
        padding-left: max(var(--space-lg), var(--safe-area-left, var(--space-lg)));
        padding-right: max(var(--space-lg), var(--safe-area-right, var(--space-lg)));
    }
}