/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --color-primary: #E4C1F9;
    --color-secondary: #F6DFEB;
    --color-accent: #D0F4DE;
    --color-highlight: #FCF6BD;
    --color-warm: #FFB7C5;
    
    /* Semantic Colors */
    --color-background: #FEFEFE;
    --color-surface: #FFFFFF;
    --color-text-primary: #2D3748;
    --color-text-secondary: #4A5568;
    --color-text-muted: #718096;
    --color-border: #E2E8F0;
    --color-shadow: rgba(0, 0, 0, 0.1);
    
    /* Dark Mode Colors */
    --color-dark-background: #1A202C;
    --color-dark-surface: #2D3748;
    --color-dark-text-primary: #F7FAFC;
    --color-dark-text-secondary: #E2E8F0;
    --color-dark-text-muted: #A0AEC0;
    --color-dark-border: #4A5568;
    --color-dark-shadow: rgba(0, 0, 0, 0.3);
    
    /* Typography */
    --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 var(--color-shadow);
    --shadow-md: 0 4px 6px -1px var(--color-shadow);
    --shadow-lg: 0 10px 15px -3px var(--color-shadow);
    --shadow-xl: 0 20px 25px -5px var(--color-shadow);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
    
    /* Z-Index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --color-background: var(--color-dark-background);
    --color-surface: var(--color-dark-surface);
    --color-text-primary: var(--color-dark-text-primary);
    --color-text-secondary: var(--color-dark-text-secondary);
    --color-text-muted: var(--color-dark-text-muted);
    --color-border: var(--color-dark-border);
    --color-shadow: var(--color-dark-shadow);
}

/* Base Styles */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-primary);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-background);
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

/* Layout Components */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section__title {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    background: linear-gradient(135deg, var(--color-primary), var(--color-warm));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--color-secondary), var(--color-primary));
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.navbar__brand {
    flex: 1;
}

.navbar__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-primary);
    margin: 0;
}

.navbar__actions {
    display: flex;
    gap: var(--spacing-sm);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--transition-fast);
    min-height: 44px;
    min-width: 44px;
}

.btn--primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-warm));
    color: var(--color-text-primary);
    box-shadow: var(--shadow-sm);
}

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

.btn--secondary {
    background-color: var(--color-surface);
    color: var(--color-text-primary);
    border: 2px solid var(--color-border);
}

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

.btn--icon {
    padding: var(--spacing-sm);
    background: transparent;
    border: none;
    border-radius: var(--radius-full);
}

.btn--icon:hover {
    background-color: var(--color-accent);
}

/* Icons */
.icon {
    width: 24px;
    height: 24px;
    display: inline-block;
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
}

.icon--theme::before {
    content: '🌙';
    font-size: 20px;
}

[data-theme="dark"] .icon--theme::before {
    content: '☀️';
}

.icon--settings::before {
    content: '⚙️';
    font-size: 20px;
}

.icon--info::before {
    content: 'ℹ️';
    font-size: 20px;
}

.icon--close::before {
    content: '✕';
    font-size: 18px;
}

/* Main Content */
.main {
    min-height: calc(100vh - 200px);
    padding: var(--spacing-2xl) var(--spacing-md);
}

/* Mode Selection */
.mode-selection {
    margin-bottom: var(--spacing-3xl);
}

.mode-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.mode-card {
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: 2px solid transparent;
}

.mode-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.mode-card.active {
    background: linear-gradient(135deg, var(--color-accent), var(--color-highlight));
    border-color: var(--color-primary);
}

.mode-card__icon {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--spacing-md);
}

.mode-card__title {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
}

.mode-card__description {
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.mode-card__pattern {
    background-color: var(--color-primary);
    color: var(--color-text-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: var(--font-size-sm);
}

/* Breathing Session */
.breathing-session {
    margin-bottom: var(--spacing-3xl);
    display: none;
}

.breathing-session.active {
    display: block;
}

.breathing-container {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.breathing-circle {
    width: 300px;
    height: 300px;
    margin: 0 auto var(--spacing-2xl);
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-warm));
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-slow);
    box-shadow: var(--shadow-xl);
    position: relative;
    overflow: hidden;
}

.breathing-circle::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
    100% { transform: translateX(100%) translateY(100%) rotate(45deg); }
}

.breathing-circle__inner {
    width: 240px;
    height: 240px;
    background: var(--color-surface);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: inset var(--shadow-lg);
    position: relative;
    z-index: 1;
}

.breathing-text {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--color-text-primary);
    text-shadow: 0 2px 4px var(--color-shadow);
}

/* Breathing Animations */
.breathing-circle--inhale {
    transform: scale(1.2);
}

.breathing-circle--exhale {
    transform: scale(0.8);
}

.breathing-circle--hold {
    transform: scale(1.1);
}

/* Session Info */
.session-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-lg);
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.session-timer {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--color-primary);
}

.cycle-counter {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
}

/* Session Controls */
.session-controls {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

/* Quick Tips */
.quick-tips {
    margin-bottom: var(--spacing-3xl);
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.tip-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-fast);
}

.tip-card:hover {
    transform: translateY(-2px);
}

.tip-card__icon {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-md);
}

.tip-card__title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

.tip-card__text {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-modal);
    display: none;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal__backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal__content {
    position: relative;
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    animation: modalSlideIn var(--transition-normal);
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.modal__title {
    font-size: var(--font-size-xl);
    margin: 0;
}

.modal__close {
    padding: var(--spacing-xs);
}

.modal__body {
    padding: var(--spacing-lg);
}

.modal__footer {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    padding: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

/* Settings */
.settings-group {
    margin-bottom: var(--spacing-xl);
}

.settings-group__title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.settings-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.settings-label {
    font-weight: 500;
    color: var(--color-text-primary);
}

.settings-input {
    width: 80px;
    padding: var(--spacing-sm);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    background: var(--color-surface);
    color: var(--color-text-primary);
}

.settings-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(228, 193, 249, 0.2);
}

/* Toggle Switch */
.toggle-switch {
    position: relative;
    width: 50px;
    height: 24px;
}

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

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

.toggle-switch__label::before {
    position: absolute;
    content: '';
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    border-radius: 50%;
    transition: var(--transition-fast);
}

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

.toggle-switch input:checked + .toggle-switch__label::before {
    transform: translateX(26px);
}

/* Offcanvas */
.offcanvas {
    position: fixed;
    top: 0;
    right: -100%;
    width: 100%;
    height: 100%;
    z-index: var(--z-modal);
    transition: right var(--transition-normal);
}

.offcanvas.active {
    right: 0;
}

.offcanvas__backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.offcanvas__content {
    position: absolute;
    top: 0;
    right: 0;
    width: 400px;
    height: 100%;
    background: var(--color-surface);
    box-shadow: var(--shadow-xl);
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
}

.offcanvas.active .offcanvas__content {
    transform: translateX(0);
}

.offcanvas__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    background: var(--color-surface);
    z-index: 1;
}

.offcanvas__title {
    font-size: var(--font-size-xl);
    margin: 0;
}

.offcanvas__body {
    padding: var(--spacing-lg);
}

/* Info Sections */
.info-section {
    margin-bottom: var(--spacing-2xl);
}

.info-section__title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.info-list {
    list-style: none;
    padding: 0;
}

.info-list li {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
    position: relative;
    padding-left: var(--spacing-lg);
}

.info-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: bold;
}

.technique-card {
    background: var(--color-background);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-md);
    border-left: 4px solid var(--color-primary);
}

.technique-card h4 {
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.faq-item {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.faq-item h4 {
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.resource-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.resource-link {
    color: var(--color-primary);
    text-decoration: none;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
}

.resource-link:hover {
    background-color: var(--color-accent);
}

/* Ad Banners */
.ad-banner {
    margin: var(--spacing-xl) 0;
    text-align: center;
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-secondary), var(--color-highlight));
    border-radius: var(--radius-lg);
    opacity: 0.8;
}

.ad-banner--top {
    margin-top: 0;
}

.ad-banner--bottom {
    margin-bottom: 0;
}

/* Footer */
.footer {
    background: linear-gradient(135deg, var(--color-accent), var(--color-highlight));
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    margin-top: var(--spacing-3xl);
}

.footer__content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer__text {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
    margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .navbar {
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .navbar__title {
        font-size: var(--font-size-xl);
    }
    
    .main {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .mode-cards {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .breathing-circle {
        width: 250px;
        height: 250px;
    }
    
    .breathing-circle__inner {
        width: 190px;
        height: 190px;
    }
    
    .session-info {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    .session-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .tips-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .modal__content {
        width: 95%;
        margin: var(--spacing-md);
    }
    
    .offcanvas__content {
        width: 100%;
    }
    
    .modal__footer {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .breathing-circle {
        width: 200px;
        height: 200px;
    }
    
    .breathing-circle__inner {
        width: 150px;
        height: 150px;
    }
    
    .breathing-text {
        font-size: var(--font-size-xl);
    }
    
    .session-timer {
        font-size: var(--font-size-xl);
    }
    
    .cycle-counter {
        font-size: var(--font-size-base);
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Styles */
.btn:focus,
.settings-input:focus,
.toggle-switch input:focus + .toggle-switch__label {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .modal,
    .offcanvas,
    .ad-banner {
        display: none;
    }
    
    .main {
        padding: 0;
    }
    
    * {
        background: white !important;
        color: black !important;
        box-shadow: none !important;
    }
}