:root {
    --color-primary: #7868E6;
    --color-secondary: #B8B5FF;
    --color-light: #EDEEF7;
    --color-accent: #E4FBFF;
    --color-danger: #FFB4B4;
    --color-white: #FFFFFF;
    --color-dark: #2D2D2D;
    --color-gray: #6B7280;
    --color-success: #10B981;
    
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 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-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 1rem;
    --border-radius-xl: 1.5rem;
    --border-radius-full: 9999px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;
}

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-dark);
    background-color: var(--color-light);
    background-image: 
        radial-gradient(circle at 25% 25%, var(--color-accent) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, var(--color-secondary) 0%, transparent 50%);
    background-attachment: fixed;
    min-height: 100vh;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 2px,
            rgba(255, 255, 255, 0.1) 2px,
            rgba(255, 255, 255, 0.1) 4px
        );
    pointer-events: none;
    z-index: -1;
}

.header {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-white);
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="paper" x="0" y="0" width="20" height="20" patternUnits="userSpaceOnUse"><rect width="20" height="20" fill="none"/><circle cx="10" cy="10" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23paper)"/></svg>');
    opacity: 0.3;
    pointer-events: none;
}

.header__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin: 0;
    position: relative;
    z-index: 1;
}

.header__subtitle {
    font-size: var(--font-size-lg);
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.header__content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
}

.header__logo {
    width: 80px;
    height: 80px;
    display: block;
    transition: all var(--transition-fast);
    position: relative;
    z-index: 1;
}

.header__logo:hover {
    transform: scale(1.05);
}

@media (max-width: 768px) {
    .header__content {
        gap: var(--spacing-md);
    }
    
    .header__logo {
        width: 60px;
        height: 60px;
    }
    
    .header__title {
        font-size: var(--font-size-2xl);
    }
}

.nav {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--color-white);
    box-shadow: var(--shadow-sm);
    flex-wrap: wrap;
}

.nav--desktop {
    display: flex;
}

@media (max-width: 768px) {
    .nav--desktop {
        display: none;
    }
}

.nav__button {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--border-radius-lg);
    background: var(--color-light);
    color: var(--color-dark);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.nav__button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    transition: left var(--transition-normal);
}

.nav__button:hover::before {
    left: 100%;
}

.nav__button:hover {
    background: var(--color-secondary);
    color: var(--color-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.nav__button--active {
    background: var(--color-primary);
    color: var(--color-white);
    box-shadow: var(--shadow-md);
}

.nav__icon {
    font-size: var(--font-size-lg);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    display: none;
    background: var(--color-white);
    border-top: 1px solid var(--color-light);
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
    padding-bottom: calc(var(--spacing-sm) + env(safe-area-inset-bottom));
    margin-bottom: 60px;
}

@media (max-width: 768px) {
    .bottom-nav {
        display: flex;
    }
    
    .main {
        padding-bottom: 80px;
    }
}

.bottom-nav__button {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
    border: none;
    background: none;
    color: var(--color-gray);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
}

.bottom-nav__button:hover {
    color: var(--color-primary);
}

.bottom-nav__button--active {
    color: var(--color-primary);
}

.bottom-nav__button--active::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 4px;
    background: var(--color-primary);
    border-radius: var(--border-radius-full);
}

.bottom-nav__icon {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.bottom-nav__icon svg {
    width: 100%;
    height: 100%;
    stroke: currentColor;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.bottom-nav__label {
    font-size: var(--font-size-xs);
    font-weight: 500;
    text-align: center;
    line-height: 1.2;
}

.main {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
}

.section {
    display: none;
    animation: fadeIn var(--transition-normal);
}

.section--active {
    display: block;
}

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

/* Timer Section */
.timer-container {
    max-width: 600px;
    margin: 0 auto;
}

.technique-selector {
    margin-bottom: var(--spacing-2xl);
}

.technique-selector__title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.technique-selector__options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.technique-option {
    padding: var(--spacing-lg);
    border: 2px solid var(--color-light);
    border-radius: var(--border-radius-lg);
    background: var(--color-white);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
}

.technique-option:hover {
    border-color: var(--color-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.technique-option--active {
    border-color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-white);
}

.technique-option h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.technique-option p {
    font-size: var(--font-size-sm);
    opacity: 0.9;
}

.timer-display {
    display: flex;
    justify-content: center;
    margin-bottom: var(--spacing-2xl);
}

.timer-display__circle {
    position: relative;
    width: 300px;
    height: 300px;
}

.timer-display__svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.timer-display__bg-circle {
    fill: none;
    stroke: var(--color-light);
    stroke-width: 8;
}

.timer-display__progress-circle {
    fill: none;
    stroke: var(--color-primary);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 565.48;
    stroke-dashoffset: 565.48;
    transition: stroke-dashoffset var(--transition-fast);
}

.timer-display__content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.timer-display__time {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.timer-display__phase {
    font-size: var(--font-size-lg);
    font-weight: 500;
    color: var(--color-dark);
    margin-bottom: var(--spacing-xs);
}

.timer-display__cycle {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
}

.timer-controls {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-2xl);
    flex-wrap: wrap;
}

.timer-controls__button {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.timer-controls__button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.timer-controls__button--start {
    background: var(--color-success);
    color: var(--color-white);
}

.timer-controls__button--pause {
    background: var(--color-secondary);
    color: var(--color-white);
}

.timer-controls__button--stop {
    background: var(--color-danger);
    color: var(--color-white);
}

.timer-controls__button--skip {
    background: var(--color-gray);
    color: var(--color-white);
}

.timer-controls__button:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.timer-controls__icon {
    font-size: var(--font-size-lg);
}

.timer-intervals {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.timer-intervals__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.timer-intervals__list {
    display: grid;
    gap: var(--spacing-md);
}

.interval-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-md);
    background: var(--color-light);
    transition: all var(--transition-fast);
}

.interval-item--active {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: var(--color-white);
}

.interval-item--completed {
    background: var(--color-success);
    color: var(--color-white);
}

.interval-item__number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius-full);
    background: var(--color-white);
    color: var(--color-primary);
    font-weight: 600;
    font-size: var(--font-size-sm);
}

.interval-item--active .interval-item__number {
    background: var(--color-white);
    color: var(--color-primary);
}

.interval-item--completed .interval-item__number {
    background: var(--color-white);
    color: var(--color-success);
}

.interval-item__info {
    flex: 1;
}

.interval-item__duration {
    font-weight: 600;
    font-size: var(--font-size-lg);
}

.interval-item__description {
    font-size: var(--font-size-sm);
    opacity: 0.8;
}

/* Techniques Section */
.techniques-container {
    max-width: 800px;
    margin: 0 auto;
}

.techniques-container__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--color-primary);
}

.technique-card {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.technique-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.technique-card__title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.technique-card__content h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin: var(--spacing-lg) 0 var(--spacing-md) 0;
    color: var(--color-dark);
}

.technique-card__content ol {
    margin-left: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.technique-card__content li {
    margin-bottom: var(--spacing-sm);
}

.technique-card__content p {
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.technique-card__content strong {
    color: var(--color-primary);
}

/* Progress Section */
.progress-container {
    max-width: 900px;
    margin: 0 auto;
}

.progress-container__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--color-primary);
}

.progress-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.progress-stat {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.progress-stat:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.progress-stat__value {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.progress-stat__label {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
    font-weight: 500;
}

.progress-chart {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-md);
}

.progress-chart__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.progress-chart__container {
    display: flex;
    align-items: end;
    gap: var(--spacing-sm);
    height: 200px;
    padding: var(--spacing-md);
    border-radius: var(--border-radius-md);
    background: var(--color-light);
}

.chart-bar {
    flex: 1;
    background: linear-gradient(to top, var(--color-primary), var(--color-secondary));
    border-radius: var(--border-radius-sm);
    min-height: 10px;
    transition: all var(--transition-fast);
    position: relative;
}

.chart-bar:hover {
    transform: scaleY(1.1);
}

.chart-bar__tooltip {
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-dark);
    color: var(--color-white);
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-xs);
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-fast);
}

.chart-bar:hover .chart-bar__tooltip {
    opacity: 1;
}

.progress-history {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.progress-history__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.progress-history__list {
    display: grid;
    gap: var(--spacing-md);
    max-height: 400px;
    overflow-y: auto;
}

.history-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-md);
    background: var(--color-light);
    transition: all var(--transition-fast);
}

.history-item:hover {
    background: var(--color-accent);
}

.history-item__icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius-full);
    background: var(--color-primary);
    color: var(--color-white);
    font-size: var(--font-size-lg);
}

.history-item__content {
    flex: 1;
}

.history-item__title {
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.history-item__details {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
}

.history-item__rating {
    display: flex;
    gap: var(--spacing-xs);
    font-size: var(--font-size-sm);
}

/* Settings Section */
.settings-container {
    max-width: 600px;
    margin: 0 auto;
}

.settings-container__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    color: var(--color-primary);
}

.settings-group {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.settings-group__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
}

.settings-option {
    margin-bottom: var(--spacing-lg);
}

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

.settings-option__label {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-weight: 500;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.settings-option__label:hover {
    color: var(--color-primary);
}

.settings-option__checkbox {
    display: none;
}

.settings-option__checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-gray);
    border-radius: var(--border-radius-sm);
    position: relative;
    transition: all var(--transition-fast);
}

.settings-option__checkbox:checked + .settings-option__checkmark {
    background: var(--color-primary);
    border-color: var(--color-primary);
}

.settings-option__checkbox:checked + .settings-option__checkmark::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--color-white);
    font-size: var(--font-size-xs);
    font-weight: 700;
}

.settings-option__range {
    flex: 1;
    margin: 0 var(--spacing-md);
    appearance: none;
    height: 6px;
    border-radius: var(--border-radius-full);
    background: var(--color-light);
    outline: none;
}

.settings-option__range::-webkit-slider-thumb {
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: var(--border-radius-full);
    background: var(--color-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.settings-option__range::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.settings-option__value {
    font-weight: 600;
    color: var(--color-primary);
    min-width: 40px;
}

.settings-option__input {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--color-light);
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-fast);
    width: 100px;
}

.settings-option__input:focus {
    outline: none;
    border-color: var(--color-primary);
}

.settings-button {
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-right: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.settings-button {
    background: var(--color-primary);
    color: var(--color-white);
}

.settings-button--danger {
    background: var(--color-danger);
    color: var(--color-white);
}

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

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal.modal--active {
    opacity: 1;
    visibility: visible;
}

.modal__content {
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-2xl);
    max-width: 400px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

.modal.modal--active .modal__content {
    transform: scale(1);
}

.modal__title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    text-align: center;
    color: var(--color-primary);
}

.rating-stars {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.rating-star {
    background: none;
    border: none;
    font-size: var(--font-size-2xl);
    cursor: pointer;
    transition: all var(--transition-fast);
    opacity: 0.3;
}

.rating-star:hover,
.rating-star.rating-star--active {
    opacity: 1;
    transform: scale(1.1);
}

.modal__textarea {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--color-light);
    border-radius: var(--border-radius-md);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    resize: vertical;
    min-height: 100px;
    margin-bottom: var(--spacing-lg);
    transition: border-color var(--transition-fast);
}

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

.modal__buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
}

.modal__button {
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.modal__button--primary {
    background: var(--color-primary);
    color: var(--color-white);
}

.modal__button--secondary {
    background: var(--color-light);
    color: var(--color-dark);
}

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

/* Loading */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.loading.loading--active {
    opacity: 1;
    visibility: visible;
}

.loading__spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--color-light);
    border-top: 4px solid var(--color-primary);
    border-radius: var(--border-radius-full);
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-lg);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading__text {
    font-size: var(--font-size-lg);
    font-weight: 500;
    color: var(--color-primary);
}

/* Toast */
.toast-container {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1500;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius-lg);
    color: var(--color-white);
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    max-width: 300px;
}

.toast.toast--show {
    transform: translateX(0);
}

.toast--success {
    background: var(--color-success);
}

.toast--error {
    background: var(--color-danger);
}

.toast--info {
    background: var(--color-primary);
}

/* Footer */
.footer {
    background: var(--color-dark);
    color: var(--color-white);
    padding: var(--spacing-lg);
    text-align: center;
    margin-top: var(--spacing-2xl);
    margin-bottom: 140px;
}

.footer__text {
    font-size: var(--font-size-sm);
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .header__title {
        font-size: var(--font-size-2xl);
    }
    
    .header__subtitle {
        font-size: var(--font-size-base);
    }
    
    .nav {
        padding: var(--spacing-sm);
    }
    
    .nav__button {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-xs);
    }
    
    .main {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .timer-display__circle {
        width: 250px;
        height: 250px;
    }
    
    .timer-display__time {
        font-size: var(--font-size-3xl);
    }
    
    .timer-controls {
        gap: var(--spacing-sm);
    }
    
    .timer-controls__button {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-sm);
    }
    
    .technique-selector__options {
        grid-template-columns: 1fr;
    }
    
    .progress-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .modal__content {
        padding: var(--spacing-lg);
    }
    
    .toast-container {
        top: var(--spacing-md);
        right: var(--spacing-md);
        left: var(--spacing-md);
    }
    
    .toast {
        max-width: none;
    }
}

@media (max-width: 480px) {
    .progress-stats {
        grid-template-columns: 1fr;
    }
    
    .timer-display__circle {
        width: 200px;
        height: 200px;
    }
    
    .timer-display__time {
        font-size: var(--font-size-2xl);
    }
    
    .nav__button {
        flex-direction: column;
        gap: var(--spacing-xs);
        padding: var(--spacing-sm);
    }
    
    .nav__icon {
        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 for keyboard navigation */
button:focus,
input:focus,
textarea:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-primary: #000080;
        --color-secondary: #000060;
        --color-light: #f0f0f0;
        --color-dark: #000000;
    }
}