/*
common element shares by all the screens
*/
/* define the reused values/use logical names for values */
:root {
    --full-height: 100dvh;
    --full-width: 100dvw;
    --landscape-width: 50dvw;
    --button-hor-margin-landscape: 1vw;
    --button-hor-margin-portrait: 1.5vw;

    /* color system */
    --base-bg: #0a0a0a;
    --surface: #141414;
    --surface-hover: #1e1e1e;
    --border: #2a2a2a;
    --text-primary: #e8e8e8;
    --text-secondary: #a0a0a0;
    --text-hint: #666;
    --accent: #4a9eff;
    --danger: #ff4a4a;
    --success: #4aff7a;
}

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

body {
    height: fit-content;
    width: 100vw;
    background-color: var(--base-bg);
    color: var(--text-primary);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* page transition system */
.page-root {
    opacity: 0;
    transition: opacity 0.2s ease-in-out;
}
.page-root.visible {
    opacity: 1;
}

/* loading spinner */
.loading-spinner {
    display: inline-block;
    width: 1.5em;
    height: 1.5em;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* toast notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100%);
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    z-index: 9999;
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
    font-size: clamp(0.8rem, 2vw, 1rem);
}
.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}
.toast.error { border-color: var(--danger); }
.toast.success { border-color: var(--success); }

/* safe area handling for notched devices */
@supports (padding: env(safe-area-inset-top)) {
    body {
        padding-top: env(safe-area-inset-top);
        padding-bottom: env(safe-area-inset-bottom);
        padding-left: env(safe-area-inset-left);
        padding-right: env(safe-area-inset-right);
    }
}

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

/* focus visibility for keyboard navigation */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* scrollbar styling */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--base-bg);
}
::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

/* input and button base styling */
input[type="text"], input[type="button"], textarea, select {
    background-color: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: 0.375rem;
    padding: 0.5em 0.75em;
    font-family: inherit;
    font-size: inherit;
    transition: border-color 0.15s ease;
}
input[type="text"]:focus, textarea:focus, select:focus {
    border-color: var(--accent);
    outline: none;
}
input[type="button"] {
    cursor: pointer;
    transition: background-color 0.15s ease;
}
input[type="button"]:hover {
    background-color: var(--surface-hover);
}
input[type="button"]:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}