/* ===== Base Reset & Variables ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Base Colors */
    --color-bg: #0a0a0a;
    --color-surface: #141414;
    --color-border: #2a2a2a;
    --color-text: #fafafa;
    --color-text-muted: #888;
    --color-accent: #fff;
    
    /* Kelly Palette - Hard-Edge Colors */
    --kelly-red: #D32F2F;
    --kelly-blue: #1565C0;
    --kelly-yellow: #F9A825;
    --kelly-green: #2E7D32;
    --kelly-black: #212121;
    --kelly-white: #FAFAFA;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    
    /* Spacing */
    --safe-area-top: env(safe-area-inset-top, 0px);
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

body {
    font-family: var(--font-primary);
    background: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    min-height: 100dvh;
    overflow: hidden;
    -webkit-tap-highlight-color: transparent;
}

/* ===== Screen Management ===== */
.screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    height: 100dvh;
    display: none;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.screen.active {
    display: flex;
    opacity: 1;
}

/* ===== Start Screen ===== */
#start-screen {
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 100%);
    padding: 1rem;
    padding-top: calc(1rem + var(--safe-area-top));
    padding-bottom: calc(1rem + var(--safe-area-bottom));
    overflow-y: auto;
}

.start-container {
    text-align: center;
    max-width: 480px;
    width: 100%;
    padding: 2rem;
}

/* ===== Kelly Color Accent Bar ===== */
.kelly-accent {
    display: flex;
    height: 6px;
    margin-bottom: 2rem;
    border-radius: 3px;
    overflow: hidden;
}

.kelly-accent span {
    flex: 1;
}

.kelly-accent span:nth-child(1) { background: var(--kelly-red); }
.kelly-accent span:nth-child(2) { background: var(--kelly-blue); }
.kelly-accent span:nth-child(3) { background: var(--kelly-yellow); }
.kelly-accent span:nth-child(4) { background: var(--kelly-green); }

/* ===== Title ===== */
.title {
    font-size: 2.5rem;
    font-weight: 300;
    letter-spacing: 0.4em;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    line-height: 1.2;
}

.subtitle {
    font-size: 0.875rem;
    font-weight: 400;
    letter-spacing: 0.2em;
    color: var(--color-text-muted);
    text-transform: uppercase;
    margin-bottom: 2.5rem;
}

/* ===== Settings Panel ===== */
.settings-panel {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.setting-group {
    margin-bottom: 1.5rem;
}

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

.setting-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    margin-bottom: 0.75rem;
}

/* ===== Preset Buttons ===== */
.preset-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

.preset-btn {
    background: transparent;
    border: 2px solid var(--color-border);
    color: var(--color-text-muted);
    padding: 0.875rem 1rem;
    font-family: var(--font-primary);
    font-size: 0.8rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition-fast);
    min-height: 48px;
    touch-action: manipulation;
}

.preset-btn:hover {
    border-color: var(--color-text-muted);
    color: var(--color-text);
}

.preset-btn.active {
    background: var(--kelly-blue);
    border-color: var(--kelly-blue);
    color: var(--kelly-white);
}

/* Custom Size Inputs */
.custom-size {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 0.75rem;
}

.custom-size.hidden {
    display: none;
}

.custom-size input {
    width: 100px;
    background: transparent;
    border: 2px solid var(--color-border);
    color: var(--color-text);
    padding: 0.75rem;
    font-family: var(--font-primary);
    font-size: 1rem;
    border-radius: 6px;
    text-align: center;
    min-height: 48px;
}

.custom-size input:focus {
    outline: none;
    border-color: var(--kelly-blue);
}

.size-separator {
    color: var(--color-text-muted);
    font-size: 1.25rem;
}

/* ===== Toggle Buttons ===== */
.toggle-container {
    display: flex;
    gap: 0.5rem;
}

.toggle-btn {
    flex: 1;
    background: transparent;
    border: 2px solid var(--color-border);
    color: var(--color-text-muted);
    padding: 0.875rem 1rem;
    font-family: var(--font-primary);
    font-size: 0.8rem;
    font-weight: 500;
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition-fast);
    min-height: 48px;
    touch-action: manipulation;
}

.toggle-btn:hover {
    border-color: var(--color-text-muted);
    color: var(--color-text);
}

.toggle-btn.active {
    background: var(--kelly-red);
    border-color: var(--kelly-red);
    color: var(--kelly-white);
}

/* ===== Primary Button ===== */
.primary-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    background: var(--color-text);
    border: none;
    color: var(--color-bg);
    padding: 1rem 2.5rem;
    font-family: var(--font-primary);
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    border-radius: 50px;
    cursor: pointer;
    transition: all var(--transition-fast);
    min-height: 56px;
    touch-action: manipulation;
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 255, 255, 0.15);
}

.primary-btn:active {
    transform: translateY(0);
}

.primary-btn svg {
    transition: transform var(--transition-fast);
}

.primary-btn:hover svg {
    transform: translateX(4px);
}

/* ===== Art Screen ===== */
#art-screen {
    justify-content: center;
    align-items: center;
    background: var(--color-bg);
}

#canvas-container {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
    padding: 1rem;
}

#canvas-container canvas {
    max-width: calc(100vw - 2rem);
    max-height: calc(100vh - 120px);
    max-height: calc(100dvh - 120px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

/* ===== Controls Overlay ===== */
.controls-overlay {
    position: fixed;
    bottom: 1.5rem;
    bottom: calc(1.5rem + var(--safe-area-bottom));
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    opacity: 1;
    transition: opacity var(--transition-normal);
    z-index: 100;
}

/* Desktop: fade in on hover */
@media (hover: hover) {
    .controls-overlay {
        opacity: 0;
    }
    
    #art-screen:hover .controls-overlay,
    #art-screen:focus-within .controls-overlay,
    .controls-overlay.visible {
        opacity: 1;
    }
}

.control-group {
    display: flex;
    background: rgba(20, 20, 20, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--color-border);
    border-radius: 50px;
    padding: 0.375rem;
    gap: 0.125rem;
}

.control-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: transparent;
    border: none;
    color: var(--color-text-muted);
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-fast);
    touch-action: manipulation;
}

.control-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-text);
}

.control-btn:active {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(0.95);
}

/* Kelly color accents on control buttons */
#regenerate-btn:hover { color: var(--kelly-green); }
#color-btn:hover { color: var(--kelly-yellow); }
#save-btn:hover { color: var(--kelly-blue); }
#copy-btn:hover { color: var(--kelly-red); }

#back-btn {
    background: rgba(20, 20, 20, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--color-border);
}

/* ===== Toast Notification ===== */
.toast {
    position: fixed;
    bottom: 7rem;
    bottom: calc(7rem + var(--safe-area-bottom));
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    background: rgba(20, 20, 20, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--color-border);
    color: var(--color-text);
    padding: 0.875rem 1.5rem;
    font-size: 0.875rem;
    border-radius: 50px;
    opacity: 0;
    transition: all var(--transition-normal);
    pointer-events: none;
    z-index: 200;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.toast.hidden {
    display: none;
}

/* ===== Responsive - Tablet ===== */
@media (max-width: 768px) {
    .start-container {
        padding: 1.5rem;
    }
    
    .title {
        font-size: 2rem;
        letter-spacing: 0.3em;
    }
    
    .subtitle {
        font-size: 0.8rem;
        margin-bottom: 2rem;
    }
    
    .settings-panel {
        padding: 1.25rem;
    }
    
    #canvas-container canvas {
        max-height: calc(100vh - 140px);
        max-height: calc(100dvh - 140px);
    }
}

/* ===== Responsive - Mobile ===== */
@media (max-width: 540px) {
    .start-container {
        padding: 1rem;
    }
    
    .title {
        font-size: 1.5rem;
        letter-spacing: 0.2em;
    }
    
    .subtitle {
        font-size: 0.7rem;
        letter-spacing: 0.15em;
    }
    
    .kelly-accent {
        height: 4px;
        margin-bottom: 1.5rem;
    }
    
    .settings-panel {
        padding: 1rem;
        border-radius: 10px;
    }
    
    .setting-group {
        margin-bottom: 1.25rem;
    }
    
    .preset-buttons {
        grid-template-columns: 1fr 1fr;
        gap: 0.375rem;
    }
    
    .preset-btn {
        font-size: 0.7rem;
        padding: 0.75rem 0.5rem;
        min-height: 44px;
    }
    
    .toggle-btn {
        font-size: 0.75rem;
        padding: 0.75rem 0.5rem;
        min-height: 44px;
    }
    
    .custom-size {
        gap: 0.5rem;
    }
    
    .custom-size input {
        width: 80px;
        padding: 0.625rem;
        font-size: 0.875rem;
        min-height: 44px;
    }
    
    .primary-btn {
        padding: 0.875rem 2rem;
        font-size: 0.8rem;
        min-height: 52px;
    }
    
    /* Art Screen Mobile */
    #canvas-container {
        padding: 0.75rem;
    }
    
    #canvas-container canvas {
        max-width: calc(100vw - 1.5rem);
        max-height: calc(100vh - 100px);
        max-height: calc(100dvh - 100px);
    }
    
    /* Controls Mobile */
    .controls-overlay {
        bottom: 1rem;
        bottom: calc(1rem + var(--safe-area-bottom));
        gap: 0.5rem;
        width: calc(100% - 2rem);
        justify-content: center;
    }
    
    .control-group {
        padding: 0.25rem;
        gap: 0.0625rem;
    }
    
    .control-btn {
        width: 44px;
        height: 44px;
    }
    
    .control-btn svg {
        width: 20px;
        height: 20px;
    }
    
    .toast {
        bottom: 5.5rem;
        bottom: calc(5.5rem + var(--safe-area-bottom));
        padding: 0.75rem 1.25rem;
        font-size: 0.8rem;
    }
}

/* ===== Responsive - Small Mobile ===== */
@media (max-width: 360px) {
    .title {
        font-size: 1.25rem;
        letter-spacing: 0.15em;
    }
    
    .subtitle {
        font-size: 0.65rem;
    }
    
    .preset-btn {
        font-size: 0.65rem;
        padding: 0.625rem 0.375rem;
    }
    
    .control-btn {
        width: 40px;
        height: 40px;
    }
    
    .control-btn svg {
        width: 18px;
        height: 18px;
    }
}

/* ===== Landscape Mobile ===== */
@media (max-height: 500px) and (orientation: landscape) {
    #start-screen {
        align-items: flex-start;
    }
    
    .start-container {
        padding: 0.75rem;
    }
    
    .title {
        font-size: 1.25rem;
        margin-bottom: 0.25rem;
    }
    
    .subtitle {
        margin-bottom: 1rem;
    }
    
    .kelly-accent {
        margin-bottom: 1rem;
    }
    
    .settings-panel {
        padding: 0.75rem;
        margin-bottom: 1rem;
    }
    
    .setting-group {
        margin-bottom: 0.75rem;
    }
    
    .preset-btn,
    .toggle-btn {
        padding: 0.5rem;
        min-height: 40px;
    }
    
    .primary-btn {
        padding: 0.75rem 1.5rem;
        min-height: 44px;
    }
    
    #canvas-container canvas {
        max-height: calc(100vh - 80px);
        max-height: calc(100dvh - 80px);
    }
    
    .controls-overlay {
        bottom: 0.5rem;
    }
}