/* ========================================
   CSS Reset & Base
   ======================================== */

*, *::before, *::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img, picture, video, canvas, svg {
    display: block;
    max-width: 100%;
}

input, button, textarea, select {
    font: inherit;
}

button {
    cursor: pointer;
}

/* ========================================
   Design System - CSS Variables
   ======================================== */

:root {
    /* Colors - Light Mode */
    --color-black: #000000;
    --color-yellow: #FFD700;
    --color-yellow-dark: #E6C200;
    --color-gray-50: #FAFAFA;
    --color-gray-100: #F5F5F5;
    --color-gray-200: #EEEEEE;
    --color-gray-300: #E0E0E0;
    --color-gray-400: #BDBDBD;
    --color-gray-500: #9E9E9E;
    --color-gray-600: #757575;
    --color-gray-700: #616161;
    --color-gray-800: #424242;
    --color-gray-900: #212121;
    --color-white: #FFFFFF;

    /* Semantic Colors */
    --color-bg: var(--color-white);
    --color-bg-secondary: var(--color-gray-50);
    --color-bg-tertiary: var(--color-gray-100);
    --color-text: var(--color-black);
    --color-text-secondary: var(--color-gray-700);
    --color-text-tertiary: var(--color-gray-600);
    --color-border: var(--color-gray-300);
    --color-primary: var(--color-yellow);
    --color-primary-hover: var(--color-yellow-dark);
    --color-danger: #DC3545;
    --color-danger-hover: #C82333;

    /* Spacing */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --space-10: 40px;
    --space-12: 48px;
    --space-16: 64px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);

    /* Layout */
    --header-height: 56px;
    --tab-bar-height: 72px;
    --safe-area-top: env(safe-area-inset-top, 0px);
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
    --safe-area-left: env(safe-area-inset-left, 0px);
    --safe-area-right: env(safe-area-inset-right, 0px);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: var(--color-black);
        --color-bg-secondary: var(--color-gray-900);
        --color-bg-tertiary: var(--color-gray-800);
        --color-text: var(--color-white);
        --color-text-secondary: var(--color-gray-400);
        --color-text-tertiary: var(--color-gray-500);
        --color-border: var(--color-gray-800);
    }
}

/* ========================================
   Base Styles
   ======================================== */

body {
    background: var(--color-bg);
    color: var(--color-text);
    overflow: hidden;
    position: fixed;
    width: 100%;
    height: 100%;
}

/* ========================================
   Bootstrap Screen
   ======================================== */

.bootstrap-screen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.bootstrap-content {
    text-align: center;
    padding: var(--space-8);
}

.app-logo {
    margin: 0 auto var(--space-6);
}

.app-name {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--space-3);
    color: var(--color-text);
}

.bootstrap-status {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-6);
}

/* ========================================
   Modal
   ======================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
}

.modal[hidden] {
    display: none;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    max-width: 400px;
    width: 100%;
    box-shadow: var(--shadow-lg);
}

.modal-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: var(--space-3);
    color: var(--color-text);
}

.modal-message {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-4);
    line-height: 1.6;
}

.modal-status {
    font-size: 14px;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-4);
}

/* Login Form */
.login-form {
    margin-top: var(--space-4);
}

/* ========================================
   Spinner
   ======================================== */

.spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto var(--space-4);
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* ========================================
   App Chrome
   ======================================== */

.app-chrome {
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
}

.app-chrome[hidden] {
    display: none;
}

/* ========================================
   Header
   ======================================== */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: calc(var(--header-height) + var(--safe-area-top));
    padding-top: var(--safe-area-top);
    padding-left: calc(var(--space-4) + var(--safe-area-left));
    padding-right: calc(var(--space-4) + var(--safe-area-right));
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

.header-title {
    font-size: 17px;
    font-weight: 600;
    color: var(--color-text);
}

/* ========================================
   Content
   ======================================== */

.content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    margin-top: calc(var(--header-height) + var(--safe-area-top));
    margin-bottom: calc(var(--tab-bar-height) + var(--safe-area-bottom));
    padding: var(--space-4);
}

/* ========================================
   Tab Bar
   ======================================== */

.tab-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: calc(var(--tab-bar-height) + var(--safe-area-bottom));
    padding-bottom: var(--safe-area-bottom);
    padding-left: var(--safe-area-left);
    padding-right: var(--safe-area-right);
    background: var(--color-bg);
    border-top: 1px solid var(--color-border);
    display: flex;
    align-items: flex-start;
    justify-content: space-around;
    z-index: 100;
}

.tab-button {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-1);
    min-height: 60px;
    padding: var(--space-2) var(--space-1);
    background: transparent;
    border: none;
    color: var(--color-text-tertiary);
    transition: color var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
}

.tab-button:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: -2px;
}

.tab-button.active {
    color: var(--color-primary);
}

.tab-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.tab-label {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.01em;
}

/* ========================================
   Loading Indicator
   ======================================== */

.loading-indicator {
    position: fixed;
    top: calc(var(--header-height) + var(--safe-area-top));
    left: 0;
    right: 0;
    z-index: 101;
}

.loading-indicator[hidden] {
    display: none;
}

.loading-bar {
    height: 3px;
    background: var(--color-primary);
    animation: loading 1s ease-in-out infinite;
}

@keyframes loading {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* ========================================
   Toast
   ======================================== */

.toast-container {
    position: fixed;
    bottom: calc(var(--tab-bar-height) + var(--safe-area-bottom) + var(--space-4));
    left: var(--space-4);
    right: var(--space-4);
    z-index: 10001;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    pointer-events: none;
}

.toast {
    background: var(--color-gray-900);
    color: var(--color-white);
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-lg);
    font-size: 14px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity var(--transition-base), transform var(--transition-base);
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

@media (prefers-color-scheme: dark) {
    .toast {
        background: var(--color-gray-200);
        color: var(--color-black);
    }
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-4);
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
    text-decoration: none;
    transition: all var(--transition-fast);
    min-height: 44px;
    -webkit-tap-highlight-color: transparent;
}

.btn:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.btn-primary {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-black);
}

.btn-primary:hover {
    background: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
}

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

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

.btn-danger {
    background: var(--color-danger);
    border-color: var(--color-danger);
    color: var(--color-white);
}

.btn-danger:hover {
    background: var(--color-danger-hover);
    border-color: var(--color-danger-hover);
}

.btn-full {
    width: 100%;
}

/* ========================================
   Forms
   ======================================== */

.form {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.form-label {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
}

.form-input,
.form-textarea,
.form-select,
.settings-select {
    width: 100%;
    padding: var(--space-3);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-size: 16px;
    min-height: 44px;
    transition: border-color var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
}

.form-textarea {
    resize: vertical;
    font-family: inherit;
    line-height: 1.5;
}

.radio-group {
    display: flex;
    gap: var(--space-4);
}

.radio-label {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    cursor: pointer;
}

.radio-input {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.form-actions {
    display: flex;
    gap: var(--space-3);
    margin-top: var(--space-2);
}

.form-actions .btn {
    flex: 1;
}

/* ========================================
   View Components
   ======================================== */

.view-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-6);
}

.view-header h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-text);
}

.section {
    margin-top: var(--space-8);
}

.section-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-4);
}

/* ========================================
   Cards
   ======================================== */

.card-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-4);
}

.card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-icon svg {
    width: 24px;
    height: 24px;
    stroke: var(--color-white);
}

.card-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text);
}

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

/* ========================================
   Lists
   ======================================== */

.list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.list-item {
    display: flex;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.list-item-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-tertiary);
}

.list-item-content {
    flex: 1;
}

.list-item-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--space-1);
}

.list-item-meta {
    font-size: 12px;
    color: var(--color-text-tertiary);
}

/* ========================================
   Search
   ======================================== */

.search-header {
    margin-bottom: var(--space-4);
}

.search-box {
    position: relative;
}

.search-icon {
    position: absolute;
    left: var(--space-3);
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-tertiary);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: var(--space-3) var(--space-3) var(--space-3) var(--space-10);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    color: var(--color-text);
    font-size: 16px;
    min-height: 44px;
}

.search-input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.search-results {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.search-result {
    display: flex;
    gap: var(--space-3);
    padding: var(--space-4);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    transition: background var(--transition-fast);
}

.search-result:active {
    background: var(--color-bg-tertiary);
}

.search-result-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-tertiary);
}

.search-result-content {
    flex: 1;
}

.search-result-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-1);
}

.search-result-desc {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-2);
}

.search-result-meta {
    display: inline-block;
    padding: var(--space-1) var(--space-2);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-sm);
    font-size: 12px;
    color: var(--color-text-tertiary);
}

/* ========================================
   Notifications
   ======================================== */

.notifications-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.notification {
    position: relative;
    display: flex;
    gap: var(--space-3);
    padding: var(--space-4);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
}

.notification.unread {
    background: var(--color-primary);
    border-color: var(--color-primary);
}

.notification.unread .notification-title,
.notification.unread .notification-text,
.notification.unread .notification-time {
    color: var(--color-black);
}

.notification.read {
    opacity: 0.6;
}

.notification-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.notification-icon svg {
    stroke: var(--color-white);
}

.notification-content {
    flex: 1;
}

.notification-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-1);
}

.notification-text {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-2);
    line-height: 1.4;
}

.notification-time {
    font-size: 12px;
    color: var(--color-text-tertiary);
}

.notification-dismiss {
    position: absolute;
    top: var(--space-2);
    right: var(--space-2);
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-tertiary);
    transition: background var(--transition-fast);
}

.notification-dismiss:hover {
    background: rgba(0, 0, 0, 0.05);
}

.notification.unread .notification-dismiss {
    color: var(--color-black);
}

/* ========================================
   Settings
   ======================================== */

.settings-section {
    margin-bottom: var(--space-8);
}

.settings-section:last-child {
    margin-bottom: 0;
}

.settings-section-title {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-3);
}

.settings-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    padding: var(--space-4) 0;
    border-bottom: 1px solid var(--color-border);
}

.settings-item:last-child {
    border-bottom: none;
}

.settings-item-content {
    flex: 1;
}

.settings-item-title {
    font-size: 16px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--space-1);
}

.settings-item-desc {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.toggle {
    position: relative;
    display: inline-block;
    width: 51px;
    height: 31px;
    flex-shrink: 0;
}

.toggle-input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-gray-400);
    transition: var(--transition-base);
    border-radius: var(--radius-full);
}

.toggle-slider:before {
    position: absolute;
    content: "";
    height: 27px;
    width: 27px;
    left: 2px;
    bottom: 2px;
    background: white;
    transition: var(--transition-base);
    border-radius: 50%;
}

.toggle-input:checked + .toggle-slider {
    background: var(--color-primary);
}

.toggle-input:checked + .toggle-slider:before {
    transform: translateX(20px);
}

.toggle-input:disabled + .toggle-slider {
    opacity: 0.5;
    cursor: not-allowed;
}

.settings-select {
    padding: var(--space-2) var(--space-3);
    min-height: auto;
}

.settings-button {
    width: 100%;
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    text-align: left;
    margin-bottom: var(--space-2);
    transition: background var(--transition-fast);
}

.settings-button:hover {
    background: var(--color-bg-tertiary);
}

.settings-button-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-tertiary);
}

.settings-button-content {
    flex: 1;
}

.settings-button-title {
    font-size: 16px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--space-1);
}

.settings-button-desc {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.settings-button-arrow {
    flex-shrink: 0;
    color: var(--color-text-tertiary);
}

.settings-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--color-border);
}

.settings-info:last-of-type {
    border-bottom: none;
    margin-bottom: var(--space-4);
}

.settings-info-label {
    font-size: 16px;
    color: var(--color-text);
}

.settings-info-value {
    font-size: 16px;
    color: var(--color-text-secondary);
}

/* ========================================
   Tips List
   ======================================== */

.tips-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.tips-list li {
    position: relative;
    padding-left: var(--space-5);
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.tips-list li:before {
    content: "•";
    position: absolute;
    left: var(--space-3);
    color: var(--color-primary);
    font-weight: bold;
}

/* ========================================
   Utilities
   ======================================== */

[hidden] {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}