:root {
    --primary: #03be99;
    --primary-dark: #029d7f;
    --primary-active: #028f73;
    --primary-light: #e6f9f5;
    --primary-surface: #f0faf7;
    --primary-disabled: #b8e5db;
    --ink: #1a1f1e;
    --body: #3d4342;
    --body-strong: #252a29;
    --muted: #6b7371;
    --muted-soft: #8e9694;
    --hairline: #dde5e2;
    --hairline-soft: #e8efec;
    --canvas: #fafbfa;
    --surface-soft: #f5f7f6;
    --surface-card: #f0f4f2;
    --surface-cream-strong: #e8edeb;
    --surface-dark: #1a1f1e;
    --surface-dark-elevated: #252b29;
    --surface-dark-soft: #1f2422;
    --on-primary: #ffffff;
    --on-dark: #fafbfa;
    --on-dark-soft: #a0a8a5;
    --error: #c64545;
    --success: #5db872;
    --warning: #d4a017;
    --accent-amber: #e8a55a;
    --shadow-sm: 0 1px 2px rgba(26, 31, 30, 0.05);
    --shadow-md: 0 4px 12px rgba(26, 31, 30, 0.07);
    --shadow-lg: 0 8px 28px rgba(26, 31, 30, 0.10);
    --shadow-xl: 0 16px 48px rgba(26, 31, 30, 0.13);
    --radius-xs: 4px;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-pill: 9999px;
    --radius-full: 9999px;
    --spacing-xxs: 4px;
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    --spacing-section: 64px;
    --font-display: 'Georgia', 'Cormorant Garamond', 'EB Garamond', 'Times New Roman', serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --font-code: 'JetBrains Mono', 'SF Mono', 'Cascadia Code', 'Consolas', 'Monaco', monospace;
    --transition-fast: 150ms ease;
    --transition-base: 220ms ease;
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-body);
    background-color: var(--canvas);
    color: var(--body);
    line-height: 1.55;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    letter-spacing: 0;
}

/* ── Top Navigation ─────────────────────────── */
.top-nav {
    background-color: var(--canvas);
    border-bottom: 1px solid var(--hairline);
    height: 60px;
    display: flex;
    align-items: center;
    padding: 0 var(--spacing-xl);
    position: sticky;
    top: 0;
    z-index: 100;
    gap: var(--spacing-md);
    flex-shrink: 0;
}
.top-nav__brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--ink);
    flex-shrink: 0;
}
.top-nav__logo {
    width: 34px;
    height: 34px;
    border-radius: var(--radius-md);
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--on-primary);
    font-weight: 700;
    font-size: 17px;
    font-family: var(--font-display);
    letter-spacing: -0.3px;
    flex-shrink: 0;
}
.top-nav__title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 400;
    letter-spacing: -0.3px;
    color: var(--ink);
    white-space: nowrap;
}
.top-nav__title span {
    color: var(--primary);
    font-weight: 400;
}
.top-nav__spacer {
    flex: 1;
}
.top-nav__status {
    font-size: 13px;
    color: var(--muted);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
}
.top-nav__status-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--hairline);
    transition: background var(--transition-base);
}
.top-nav__status-dot--active {
    background: var(--success);
    box-shadow: 0 0 0 3px rgba(93, 184, 114, 0.2);
}
.top-nav__status-dot--error {
    background: var(--error);
    box-shadow: 0 0 0 3px rgba(198, 69, 69, 0.2);
}

/* ── Main Layout ────────────────────────────── */
.main-layout {
    display: flex;
    flex: 1;
    min-height: 0;
    position: relative;
}

/* ── Sidebar ────────────────────────────────── */
.sidebar {
    width: 340px;
    flex-shrink: 0;
    border-right: 1px solid var(--hairline);
    background: var(--canvas);
    display: flex;
    flex-direction: column;
    padding: var(--spacing-lg);
    gap: var(--spacing-lg);
    overflow-y: auto;
    z-index: 10;
    transition: transform var(--transition-slow), width var(--transition-slow);
}
.sidebar__section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}
.sidebar__label {
    font-size: 12px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--muted-soft);
    margin-bottom: 2px;
    font-family: var(--font-body);
}

/* Upload Zone */
.upload-zone {
    border: 2px dashed var(--hairline);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl) var(--spacing-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    background: var(--surface-soft);
    position: relative;
    min-height: 140px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}
.upload-zone:hover {
    border-color: var(--primary);
    background: var(--primary-surface);
    box-shadow: var(--shadow-sm);
}
.upload-zone--drag-over {
    border-color: var(--primary);
    background: var(--primary-light);
    box-shadow: var(--shadow-md);
    border-style: solid;
}
.upload-zone--has-file {
    border-color: var(--primary);
    border-style: solid;
    background: var(--primary-surface);
}
.upload-zone__icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-full);
    background: var(--primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    transition: all var(--transition-base);
    flex-shrink: 0;
}
.upload-zone:hover .upload-zone__icon {
    background: var(--primary);
    color: var(--on-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.upload-zone__icon svg {
    width: 22px;
    height: 22px;
}
.upload-zone__text {
    font-size: 14px;
    font-weight: 500;
    color: var(--body-strong);
    line-height: 1.4;
}
.upload-zone__hint {
    font-size: 12px;
    color: var(--muted-soft);
    line-height: 1.4;
}
.upload-zone__file-info {
    display: none;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--surface-card);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 13px;
    font-weight: 500;
    color: var(--body-strong);
    max-width: 100%;
    overflow: hidden;
}
.upload-zone__file-info--visible {
    display: flex;
}
.upload-zone__file-name {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
    min-width: 0;
}
.upload-zone__file-remove {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: none;
    background: var(--hairline);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    color: var(--muted);
    transition: all var(--transition-fast);
    line-height: 1;
}
.upload-zone__file-remove:hover {
    background: #fdd;
    color: var(--error);
}
.upload-zone input[type="file"] {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
    z-index: 2;
}

/* Device Selector */
.device-selector {
    display: flex;
    gap: 4px;
    background: var(--surface-soft);
    border-radius: var(--radius-md);
    padding: 4px;
    flex-wrap: wrap;
}
.device-btn {
    flex: 1;
    min-width: 44px;
    height: 40px;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1px;
    font-size: 10px;
    font-weight: 500;
    color: var(--muted);
    transition: all var(--transition-fast);
    font-family: var(--font-body);
    padding: 4px 6px;
    white-space: nowrap;
    letter-spacing: 0;
}
.device-btn svg {
    width: 18px;
    height: 18px;
    transition: color var(--transition-fast);
}
.device-btn:hover {
    color: var(--body-strong);
    background: var(--surface-card);
}
.device-btn--active {
    background: var(--canvas) !important;
    color: var(--primary) !important;
    box-shadow: var(--shadow-sm);
    font-weight: 600;
}
.device-btn--active svg {
    color: var(--primary);
}

/* Refresh & Fullscreen Buttons */
.btn-refresh,
.btn-fullscreen {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 10px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--hairline);
    background: var(--canvas);
    cursor: pointer;
    font-size: 13px;
    font-weight: 500;
    color: var(--body-strong);
    font-family: var(--font-body);
    transition: all var(--transition-fast);
    width: 100%;
    letter-spacing: 0;
}
.btn-refresh:hover,
.btn-fullscreen:hover {
    background: var(--surface-soft);
    border-color: var(--primary);
    color: var(--primary);
}
.btn-refresh svg,
.btn-fullscreen svg {
    width: 15px;
    height: 15px;
    transition: transform var(--transition-base);
}
.btn-refresh:hover svg {
    transform: rotate(90deg);
}
.btn-fullscreen {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-surface);
}
.btn-fullscreen:hover {
    background: var(--primary);
    color: var(--on-primary);
}
.btn-fullscreen:disabled {
    opacity: 0.45;
    pointer-events: none;
    border-color: var(--hairline);
    color: var(--muted);
    background: var(--surface-soft);
}
.btn-fullscreen:disabled:hover {
    background: var(--surface-soft);
    color: var(--muted);
    border-color: var(--hairline);
}

/* ── Preview Area ───────────────────────────── */
.preview-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-soft);
    padding: var(--spacing-lg);
    overflow: auto;
    min-width: 0;
    position: relative;
}
.preview-area__empty {
    text-align: center;
    color: var(--muted-soft);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    pointer-events: none;
}
.preview-area__empty-icon {
    width: 72px;
    height: 72px;
    border-radius: var(--radius-full);
    background: var(--surface-card);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--hairline);
}
.preview-area__empty-icon svg {
    width: 36px;
    height: 36px;
}
.preview-area__empty h3 {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 400;
    color: var(--muted);
    letter-spacing: -0.2px;
}
.preview-area__empty p {
    font-size: 13px;
    color: var(--muted-soft);
    max-width: 280px;
    line-height: 1.5;
}

/* Device Frame Wrapper */
.device-frame-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-slow);
    flex-shrink: 0;
}
.device-frame-wrapper--desktop {
    width: 100%;
    max-width: 100%;
    height: 100%;
}
.device-frame-wrapper--mobile {
    width: 395px;
    height: 740px;
    flex-shrink: 0;
}
.device-frame-wrapper--tablet-landscape {
    width: 1056px;
    height: 700px;
    flex-shrink: 0;
}
.device-frame-wrapper--tablet-portrait {
    width: 800px;
    height: 940px;
    flex-shrink: 0;
}
.device-frame-wrapper--default {
    width: 100%;
    height: 100%;
}

/* Scale handling for smaller screens */
@media (max-width: 1300px) {
    .device-frame-wrapper--tablet-landscape {
        transform: scale(0.85);
        transform-origin: center center;
    }
    .device-frame-wrapper--tablet-portrait {
        transform: scale(0.85);
        transform-origin: center center;
    }
}
@media (max-width: 900px) {
    .device-frame-wrapper--tablet-landscape {
        transform: scale(0.6);
    }
    .device-frame-wrapper--tablet-portrait {
        transform: scale(0.6);
    }
    .device-frame-wrapper--mobile {
        transform: scale(0.85);
        transform-origin: center center;
    }
}
@media (max-width: 500px) {
    .device-frame-wrapper--mobile {
        transform: scale(0.7);
    }
}

/* Desktop Browser Frame */
.device-frame--desktop {
    width: 100%;
    height: 100%;
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--hairline);
}
.device-frame--desktop .frame-topbar {
    height: 38px;
    background: #e8ebed;
    display: flex;
    align-items: center;
    padding: 0 14px;
    gap: 8px;
    flex-shrink: 0;
    border-bottom: 1px solid #dde1e0;
}
.frame-dot {
    width: 11px;
    height: 11px;
    border-radius: 50%;
    flex-shrink: 0;
}
.frame-dot--red {
    background: #ee5a5a;
}
.frame-dot--yellow {
    background: #f5bf4f;
}
.frame-dot--green {
    background: #5ec75e;
}
.frame-address-bar {
    flex: 1;
    height: 26px;
    background: #fff;
    border-radius: 6px;
    margin: 0 10px;
    display: flex;
    align-items: center;
    padding: 0 12px;
    font-size: 11px;
    color: var(--muted-soft);
    font-family: var(--font-body);
    letter-spacing: 0;
    border: 1px solid #dde1e0;
    min-width: 0;
}
.frame-address-bar span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.device-frame--desktop iframe {
    flex: 1;
    width: 100%;
    border: none;
    background: #fff;
    min-height: 0;
}

/* Mobile Device Frame */
.device-frame--mobile {
    width: 100%;
    height: 100%;
    background: #1a1f1e;
    border-radius: 28px;
    padding: 10px;
    box-shadow: var(--shadow-xl), 0 0 0 2px #2d3231;
    display: flex;
    flex-direction: column;
    position: relative;
}
.device-frame--mobile .frame-notch {
    width: 80px;
    height: 24px;
    background: #1a1f1e;
    border-radius: 0 0 16px 16px;
    margin: 0 auto 6px;
    flex-shrink: 0;
    position: relative;
}
.device-frame--mobile .frame-notch::after {
    content: '';
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #2d3231;
}
.device-frame--mobile .frame-screen {
    flex: 1;
    border-radius: 20px;
    overflow: hidden;
    background: #fff;
    position: relative;
}
.device-frame--mobile iframe {
    width: 100%;
    height: 100%;
    border: none;
    background: #fff;
}
.device-frame--mobile .frame-home-bar {
    width: 44px;
    height: 4px;
    background: #3d4342;
    border-radius: 3px;
    margin: 8px auto 0;
    flex-shrink: 0;
}

/* Tablet Device Frame */
.device-frame--tablet {
    width: 100%;
    height: 100%;
    background: #1a1f1e;
    border-radius: 18px;
    padding: 8px;
    box-shadow: var(--shadow-xl), 0 0 0 2px #2d3231;
    display: flex;
    flex-direction: column;
}
.device-frame--tablet .frame-notch {
    width: 50px;
    height: 6px;
    background: #2d3231;
    border-radius: 3px;
    margin: 0 auto 6px;
    flex-shrink: 0;
}
.device-frame--tablet .frame-screen {
    flex: 1;
    border-radius: 12px;
    overflow: hidden;
    background: #fff;
}
.device-frame--tablet iframe {
    width: 100%;
    height: 100%;
    border: none;
    background: #fff;
}
.device-frame--tablet .frame-home-bar {
    width: 36px;
    height: 3px;
    background: #3d4342;
    border-radius: 2px;
    margin: 6px auto 0;
    flex-shrink: 0;
}

/* Default (no frame) */
.device-frame--default {
    width: 100%;
    height: 100%;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--hairline);
    background: #fff;
}
.device-frame--default iframe {
    width: 100%;
    height: 100%;
    border: none;
    background: #fff;
}

/* ── Toast ──────────────────────────────────── */
.toast-container {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 200;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    pointer-events: none;
}
.toast {
    background: var(--surface-dark);
    color: var(--on-dark);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    animation: toast-in 0.35s cubic-bezier(0.4, 0, 0.2, 1) forwards;
    pointer-events: auto;
    max-width: 340px;
    font-family: var(--font-body);
    letter-spacing: 0;
}
.toast--error {
    background: #c64545;
    color: #fff;
}
.toast--success {
    background: var(--surface-dark);
    color: var(--on-dark);
    border-left: 3px solid var(--success);
}
@keyframes toast-in {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
@keyframes toast-out {
    from {
        opacity: 1;
        transform: translateY(0);
    }
    to {
        opacity: 0;
        transform: translateY(16px);
    }
}

/* ── Responsive ─────────────────────────────── */
@media (max-width: 768px) {
    .main-layout {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        flex-shrink: 1;
        border-right: none;
        border-bottom: 1px solid var(--hairline);
        padding: var(--spacing-md);
        gap: var(--spacing-md);
        max-height: 45vh;
        overflow-y: auto;
    }
    .preview-area {
        padding: var(--spacing-md);
        min-height: 50vh;
        flex: 1;
    }
    .device-frame-wrapper--mobile {
        width: 340px;
        height: 640px;
    }
    .device-frame-wrapper--tablet-landscape {
        width: 90vw;
        height: 55vw;
    }
    .device-frame-wrapper--tablet-portrait {
        width: 55vw;
        height: 75vw;
    }
    .top-nav {
        padding: 0 var(--spacing-md);
        height: 52px;
    }
    .top-nav__title {
        font-size: 17px;
    }
    .top-nav__logo {
        width: 28px;
        height: 28px;
        font-size: 14px;
    }
    .device-selector {
        flex-wrap: nowrap;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    .device-btn {
        flex: 0 0 auto;
        min-width: 50px;
        font-size: 9px;
    }
    .upload-zone {
        min-height: 100px;
        padding: var(--spacing-md);
    }
}
@media (max-width: 420px) {
    .sidebar {
        padding: var(--spacing-sm);
        gap: var(--spacing-sm);
        max-height: 40vh;
    }
    .preview-area {
        padding: var(--spacing-xs);
    }
    .device-frame-wrapper--mobile {
        width: 280px;
        height: 530px;
        transform: scale(0.85);
    }
    .top-nav__title {
        font-size: 15px;
    }
    .top-nav__status {
        display: none;
    }
}